FIELD OF THE INVENTION The present invention is in the field of wireless telecommunications. In particular, but not exclusively, the invention relates to systems for improving cell phone signal reception in areas remote from a transmission antenna.

BACKGROUND TO THE INVENTION

Cell phone technology has undoubtedly revolutionized communication, providing the ability to make and receive telephone calls even in remote areas. Cell phone infrastructure is also used to send and receive data, allowing users to wirelessly access the Internet and also SMS text facilities.

Many remote areas have a very weak cell phone reception, thereby isolating the communities that live in these areas. Remote highways may also be plagued by poor cell phone reception meaning that motorists can be stranded without any means of communication with the outside world in an emergency. In many cases it is not economically or practically feasible to install cell phone towers to service remote areas.

As a solution to the problem of insufficient signal, the prior art discloses a number of repeater devices. For example, users of the Australian Telstra™ cell phone network in remote areas are able to purchase a repeater kit which is configured to address poor indoor Next-G phone coverage. The system comprises a high gain 16dBi Yagi antenna which is mounted externally on the roof of a building. The signal is electronically amplified and conveyed to rooms of a building by a series of repeaters. Each repeater unit fed by the antenna typically creates a 15-30m radius coverage area in normal home or office environments. While useful, this repeater system is only useful where the cell phone signal is marginal, and requires only a low level of boosting. A further problem is that the system requires electrical power to operate.

Many remote regions of highways and rural settlements have no electrical power or at most may have unreliable power. Accordingly, repeater solutions are not appropriate. While renewable energy (such as solar and wind power with battery backup batteries) may be used, these solutions are expensive and require ongoing maintenance. Quite apart from the problems recited supra, repeaters are notorious for interfering with cellular phone systems and therefore many jurisdictions have legislation to strictly regulate or even prohibit the use of cell phone repeaters. It is an aspect of the present invention to provide low cost and low maintenance means for allowing a cell phone user to make or receive a telephone call, text message or data in a remote area where a cell phone network signal is weak. It is a further aspect to provide an alternative to provide art means for allowing a cell phone user to make or receive a telephone call, text message or data in a remote area where a cell phone network signal is very weak.

The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

SUMMARY OF THE INVENTION In a first aspect, but not necessarily the broadest aspect, the present invention provides a system for improving the reception and/or transmission of a mobile communication device, the system comprising: signal focussing means configured to focus a telecommunications signal to provide a signal focus region, and positioning means configured to position a mobile communication device in or about the focus region of the signal focussing means.

In one embodiment, the mobile communication device signal focussing means comprises a curved reflector surface.

In one embodiment, the curved reflector surface is of a substantially parabolic cross-sectional profile, or a segment thereof.

In one embodiment, the curved reflective surface is, or comprises, a paraboloid, or a segment thereof. In one embodiment, the mobile communication device signal focussing means is passive. In one embodiment, the mobile communication device signal focussing means is devoid of a transducer at or about the signal focus region.

In one embodiment, the mobile communication device positioning means is configured to position a mobile communication in or about the focus region of the mobile communication device focussing means.

In one embodiment, the mobile communication device positioning means is configured to support a cell phone at a position to allow use of the hands free function of the function with the user in a standing position, or in a sitting position.

In one embodiment, the mobile communication device positioning means is supported by a platform configured to allow a user to stand thereupon. In one embodiment, the mobile communication device positioning means is configured so as to be capable of fixing the location of the mobile communication device within the signal focus region

In one embodiment, the signal focussing means is disposed on a support configured to allow the signal focussing means to be directed toward a source of mobile communication device signal.

In one embodiment, the support and the mobile communication device positioning means are separated by a fixed distance.

In one embodiment, the system is configured to be mounted on a substrate such that the mobile communication device signal focussing means is capable of being directed at a source of mobile communication device signal. In one embodiment, the system comprises means for increasing the effective height of the signal focussing means above ground level.

In one embodiment, the means for increasing the effective height of the signal focussing means above ground level is a signal reflector, the signal reflector disposed above the signal focussing means and configured to reflect a mobile communication device signal toward the signal focussing means. In one embodiment, the means for increasing the effective height of the signal focussing means above ground level comprises a waveguide configured to couple the signal reflector to the cell phone. In one embodiment, the system comprises means to increase the directivity of the signal focussing means and a mobile communication device disposed in, on or about the positioning means.

In one embodiment, the means to increase the directivity of the signal focussing means is a secondary signal reflector or a secondary signal focussing means disposed about the mobile communications device.

In one embodiment, the means to increase the directivity of the signal focussing means is disposed such that a mobile communication device disposed in, on or about the positioning means is interposed between the signal focussing means and the means to increase the directivity of the signal focussing means.

In one embodiment, the system comprises instructional signage. In a second aspect, the present invention provides a system for transmitting and/or receiving a mobile communication device signal, the system comprising the system of the first aspect, and a mobile communication device located on, in, or about the mobile communication device positioning means. In one embodiment of the system of the second aspect, the mobile communication device is a cell phone.

In a third aspect, the present invention provides a method for transmitting and/or receiving a mobile communication device signal, the method comprising the steps of: providing a signal focussing means, and allowing the signal focussing means to provide a signal focus region, and positioning the mobile communication device within the signal focus region.

In a fourth aspect, the present invention provides a method for transmitting and/or receiving a mobile communication device signal, the method comprising the steps of: providing the system of the first aspect, and positioning a mobile communication device in, on or about the mobile communication device positioning means, and causing the mobile communication device to transmit a mobile communication device signal and/or allowing the mobile communication device to receive a mobile communication device signal.

In one embodiment of the method of the fourth aspect, the mobile communication device is maintained substantially stationary for the duration of the transmission of the mobile communication device signal and/or the reception of the mobile communication device signal.

In a fifth aspect, the present invention comprises a kit of parts for constructing a system for improving the reception and/or transmission of a mobile communication device, the kit comprising:

a mobile communication device signal focussing means having a focus region, and a mobile communication device positioning means,

wherein the mobile communication device positioning means is configured to position a mobile communication device antenna in or about the focus region of the mobile communication device signal focussing means.

In one embodiment, the kit comprises a support configured to allow the signal focussing means to be directed toward a source of mobile communication device signal. In one embodiment, the kit comprises a support configured to allow mounting of the mobile communication device positioning means thereon, and to allow a user to stand thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

In seeking only to further explain the invention, it will be understood that the drawings are not intended to be read strictly. The drawings are not intended to be an accurate presentation of the geometries of the reflector dish, or the directional vectors of the cell phone signals between the tower and the reflector and between the reflector and the cell phone.

Fig. 1 shows a preferred embodiment of the system whereby a smart phone is positioned in the focus region of a parabolic reflector such that a smart phone signal is focussed about the smart phone so as to improve signal reception and transmission. The parabolic reflector is mounted on a dedicated support. The smart phone is mounted on a dedicated post. Fig. 2 shows an alternative arrangement whereby the smart phone is mounted on an external wall of a building.

Fig. 3 shows an alternative arrangement whereby the smart phone mount is disposed on the end of a member extending directly from the reflector dish support.

Fig. 4 shows an alternative arrangement whereby the reflector dish is disposed on an external wall of a building. Fig. 5 shows an alternative arrangement whereby the smart phone mount is disposed on the end of a member extending directly from the reflector dish.

Fig, 6 shows a preferred embodiment of the system having a planar signal reflector configured to increase the effective height of the reflector dish.

Fig. 7 shows a preferred embodiment of the system having a secondary signal reflector which increases the directivity of the reflector dish.

Fig. 8 shows the experimental set up for Test Case 1 , as described in Example 2 herein. Fig. 9 shows the experimental set up for Test Case 2, as described in Example 3 herein.

Fig. 10 shows the experimental set up for Test Cases 3A to 3D, as described in Example 4 herein. Fig. 1 1 shows the experimental set up for Test Case 4, as described in Example 5 herein.

Fig. 12 shows the experimental set up for Test Case 5A and 5B, as described in Example 5 herein. Fig. 13 shows the experimental set up for Test Case 6, as described in Example 6 herein.

Fig. 14 is a graph showing Signal strength for a dipole receive antenna with small reflector - no parabolic dish. Fig. 15 shows the experimental set up for Test Case 7 A, as described in Example 6 herein. Figure 16 is a graph showing Signal strength for a dipole receive antenna with sub-reflector - with parabolic dish.

Fig. 17 shows the experimental set up for Test Case 7B with phone replacing dipole antenna and spectrum analyser, as described in Example 6 herein.

Fig. 18 is a graph showing signal strength for phone with sub-reflector - with parabolic dish. Top panel shows where plat plate reflector has dimensions of λ x λ, bottom panel reflector of dimensions (λ/2) x (λ/2)

Fig. 19 is a graph showing signal strength for phone with sub-reflector - with parabolic dish - for varying sub-reflector altitude angle.

Fig. 20 shows the experimental set up for Test Case 8A and 8B, as described in Example 7 herein.

Fig. 21 shows the experimental set up for Test Case 9, as described in Example 8 herein. Fig. 22 is a graph of signal strength for integrated test, with varying sub-reflector distance

DETAILED DESCRIPTION OF THE INVENTION

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

Similarly it should be appreciated that the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and from different embodiments, as would be understood by those in the art.

For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the claims below and the description herein, any one of the terms "comprising", "comprised of" or "which comprises" is an open term that means including at least the elements/features that follow, but not excluding others. Thus, the term comprising, when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression a method comprising step A and step B should not be limited to methods consisting only of methods A and B. Any one of the terms "including" or "which includes" or "that includes" as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, "including" is synonymous with and means "comprising".

In one aspect, the present invention provides a system for improving the reception and/or transmission of a mobile communication device, the system comprising:

signal focussing means configured to focus a telecommunications to provide a signal focus region, and

positioning means configured to position a mobile communication device in or about the focus region of the signal focussing means,

wherein, in use, the positioning means is disposed in the signal focus region of the signal focussing means. In addressing the problem of low signal strength in remote areas, the Applicant has departed from prior art approaches of using powered amplified systems to increase cell phone signal, and then transmitting the amplified signal to the cell phone. Advantageously, the Applicant provides a solution that has no requirement for electrical power for amplification, does not involve any relaying of the cell phone signal, is essentially maintenance free, and furthermore cost-effective.

In the context of the present system, the signal focussing means is a physical means (as distinct from an electronic means) by which electromagnetic waves which are transmitted from a cell phone tower can be focussed into a focus region. The waves are collected across the relatively large surface area of the antenna face and concentrated into a relatively small focus region. According to the system the cell phone (or other mobile communications device) is positioned to be within the focus region. Given the unitary nature of cell phone construction, positioning the device within the focus region also locates the cell phone antenna in the focus region.

The signal focussing means may be configured to focus the incoming cell phone signal to a point, or a region, or along a line. Where the signal is focussed to a region, the region may be regularly shaped or irregularly shaped.

In terms of the outgoing transmission of the signal (i.e. the signal generated by phone encoding voice or data), the signal emanates outwardly in all directions from the cell phone antenna. While a small portion is directed toward the cell phone tower, most is normally lost in directions away from the tower. According to the present systems, the signal focussing means acts not only to focus incoming signal onto the phone, but also reflect (and optionally collimate) outgoing signal. Thus, a greater portion of the signal generated by the phone is directed toward the tower thereby improving transmission from areas remote from the tower.

The signal focussing means may be any means by which electromagnetic waves of the type used in mobile communication can be brought to a focus. Such means include any reflector having a curved (or approximately curved) surface configured to direct multiple signal waves to a focus point or region. The skilled person is familiar with such reflectors given their use in satellite communications and radar. However, the use of such reflectors as prescribed by the present systems has not precisely been described to the best of Applicant's knowledge.

In one embodiment, the signal focus means is a parabolic or near parabolic reflector. The most common form of such reflectors is substantially dish-shaped, however the systems are not restricted to such forms. An advantage of a parabolic reflector is the high degree of directivity, this being important in both receiving and transmitting signal. Parabolic reflectors provide high gains to the incoming signal. As is understood by the skilled person, in order to achieve high gain, the parabolic reflector must be significantly larger than the wavelength of the radio waves used. Parabolic antennas are used in the high frequency part of the radio spectrum, at UHF and microwave (SHF) frequencies, at which the wavelengths are small enough that conveniently-sized reflectors can be used. Such frequencies are used by mobile communication devices, such as cell phones Systems including high directional gain parabolic reflectors provide versatility in respect of the range of mobile communication devices and communication networks with which the system is operable. Such reflectors are relatively frequency independent, thereby broadening applicability. The reflector typically has a metallic or metallised surface formed into a paraboloid of revolution and usually truncated in a circular or near circular rim that forms the diameter of the antenna. The reflector may be of sheet metal, metal screen, or wire grill construction, and it may be either a circular "dish" or various other shapes to create different beam shapes. A metal screen reflects radio waves as well as a solid metal surface as long as the apertures are smaller than one-tenth of a wavelength, so screen reflectors are often used to reduce weight and wind loads on the dish.

To optimize gain, it is preferred that the shape of the dish be accurate within a small fraction of a wavelength, to ensure the waves from different parts of the antenna arrive at the focus in phase. Large dishes (as may be required in areas where the cell phone signal is extremely weak) often require a supporting truss structure behind them to provide the required stiffness.

In one embodiment, the paraboloidal or dish reflector is shaped like a paraboloid truncated in a circular rim. This radiates a narrow cone-shaped beam along the axis of the dish toward the cell phone in need of improved reception.

In one embodiment, the reflector is an offset dish whereby in cross section the dish forms part of the upper half of a paraboloid. This shape allows the focus (and any object that is placed there) to be outside the beam path between the dish and the distant tower. This improves signal gain, and has the further advantage that the dish can be placed somewhat higher relative to the cell phone and the user, which in turn increases both-way signal strength in most instances. The rim of the dish may be oval in shape, because the tilting of the dish toward the beam direction that is characteristic of an offset dish reduces the effective vertical height of the beam, which is compensated for by increasing the actual height of the paraboloidal segment. In one embodiment, the reflector is cylindrical, i.e. the reflector is curved in only one direction but is flat in the other. The signal comes to a focus not at a point, but along a line. Cylindrical parabolic antennas radiate a fan-shaped beam, narrow in the curved dimension, and wide in the uncurved dimension. In one embodiment, the reflector is a shaped beam reflector. These produce a beam or beams of a particular shape, rather than just the narrow "cone" or "fan" beams of the simple dish and cylindrical antennas above. Two techniques may be used in combination to control the shape of the beam: The signal focussing means may be directed downwardly, and toward the mobile communication device positioning means. In embodiments having a second elevated reflector (as described more fully infra), the signal focussing means may be directed upwardly. .

The signal focussing means is preferably passive, in so far as no electrical power is required for operation. For example, the use of a parabolic reflector as a signal focussing means completely obviates the need for electrical power. Furthermore, no moving parts are required and the reflector is virtually maintenance free. This is a significant advantage of the invention over prior art devices such as signal repeaters. As will be understood by the skilled person, the geographical location of the signal focussing means about a desired area, and also the direction in which the focussing means is directed will assume some importance in successful implementation of the invention. Avoidance of geographical features such as mountains, or manmade structures between the source of the signal (such as a cell phone tower) and the signal focussing means (such as a parabolic reflector) is preferred. Some basic experimentation using various locations and directions is well within the ability of the skilled person.

The reflector of the signal focussing means is sized according to the application. Typically, the weaker the signal from the tower (as recorded at the mobile device) the greater the reflector surface area required so as to collect sufficient signal to direct to the device. Similarly, the weaker the signal from the mobile device (as recorded at the tower) the greater the reflector surface area required so as to collect sufficient signal to direct to the tower. Where a cell phone signal is marginal, and a parabolic dish is used, it would be typical for the dish to have a surface area of at least about 1 .0 m ² in order to provide a usable signal. Of course, smaller surface areas are anticipated to have utility in some circumstances. For example, where an incoming signal is only marginal, a surface area of less than 1 .0 m ² may be sufficient to provide a usable signal. According, in one embodiment, where the signal focussing means has a reflector, the reflector surface area is at least about 0.1 , 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9 m ² .

Conversely, where a signal is of very low strength, a larger surface may be required. In such circumstances, it would also be generally expected that greater attention be had to precisely directing the focussing means toward the signal source. Accordingly, in one embodiment, where the signal focussing means has a reflector, the reflector surface area is at least about 1 .0, 1 .1 , 1 .2, 1 .3, 1 .4, 1 .5, 1 .6, 1 .7, 1 .8, 1 .9, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5 m ² .

In some embodiments, the signal focussing means is configured to provide at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19 or 20 dB gain in both send and receive directions.

Methods for quantifying the gain of a parabolic antenna are known, but for the sake of completeness one such method is disclosed herein being governed by the following formula

where:

is the area of the antenna aperture, that is, the mouth of the parabolic reflector, is the wavelength of the radio waves.

is a dimensionless parameter between 0 and 1 called the aperture efficiency

(the aperture efficiency of typical parabolic antennas is 0.55 to 0.70.

For a circular dish antenna, giving the second formula above Where

d is the diameter of the antenna. Generally, a doubling of dish diameter (4 times the area) yields a gain increase of about 6dB. In principle, the gain of the present system can be increased to an ever greater figure by simply increasing diameter, however the associated cost of the larger antenna and the means to mount it increases generally exponentially with diameter. For some applications a 1 .2m diameter dish provides sufficient gain. For applications where weaker signals are expected, a 1 .8m diameter dish may be preferred which provides 3.5dB of gain over the 1 .2m standard dish.

The present system comprises mobile communication device positioning means configured to position (in space) a device such as smart phone.

The positioning means functions to stably position a mobile communication device or non- integral antenna thereof in or about the focus region of the signal focussing means. This requires that the positioning means is configured so as to ensure the device is correctly positioned with respect to x, y and z co-ordinates. Typically, the positioning means is disposed along a line extending along a focal line, or at a focal point. In the latter circumstance, the positioning means is located a predetermined distance from the reflector to align with the focal point. Correct location of the positioning means can be arrived at by mathematical means to identify the focal point or line of the signal focussing means, or by empirical means. In the latter case, a signal meter can be used to locate an area of high signal about the reflector surface.

Stable positioning is preferred so as to ensure that the mobile communications device or non- integral antenna thereof remains in the high signal focus region. The positioning means may be a simple platform disposed on a support post such that a cell phone, for example, may be placed upon the platform where it rests. A ledge or border may be added to prevent the device from sliding off. Retaining means such as spring loaded clamping means may be added to better secure the device to the platform.

The positioning means may be configured so as to allow operation of a mobile communication device. Typically, a cell phone is disposed on the positioning means and used in hands-free mode. Accordingly, the positioning means should not block a microphone or speaker of the cell phone. Furthermore, it is preferable that where the cell phone is a smart phone the screen is not obstructed or obscured so as to allow a user to view and touch the screen. The post will be dimensioned so as to ensure the device support platform is in the focus region.

In some embodiments, the positioning means is a users' hand. As an example of this embodiment, the user may by trial and error assess his/her cell phone signal (as read by the familiar antenna bars on the phone screen) and move the phone about the focussing means until an acceptable signal is noted. In some embodiments, the reflector may comprise a simple string of predetermined length attached to the centre of a reflector surface such that the end of the outwardly extended string signifies the focus point of the reflector. For an offset dish the equivalent would require 3 strings to properly signify the focus point. In that embodiment, the user may clutch the end of the string with the phone in the same hand and maintain outward tension on the string to maintain the required distance between the reflector and the phone.

Of course, in such embodiments the user must attempt to maintain the phone within the focus region during use of the phone, however for short voice calls or sending SMS text messages this may not cause any practical issue.

Both the signal focussing means and positioning means may be configured such that the mobile communication device is in a position such that it is usable by a user either in a sitting or standing position. Thus, the signal focussing means may be configured so as to focus the signal at a height of between about 1 meter and 2 meters from the ground.

The positioning means may be attached to the signal focussing means, or to a support of the signal focusing means. Alternatively, the positioning means is attached to a platform that is shared with the signal focussing means. In another embodiment, the positioning means stands alone and may be a post anchored into the ground.

In some embodiments, the positioning means includes components which are not dedicated to the function of positioning the phone. For example, the external wall of building may be used to support a cell phone mount at the correct height. The reflector will be disposed the correct distance from the mount so as to ensure the phone (when placed on the mount) is within the focus region. Preferably, the system is configured such that the location of the positioning means is fixed with respect to the signal focussing means. In this way, the mobile device will always be in the correct position so as to best receive and transmit signal. In one embodiment, the positioning means is configured so as to position the mobile telecommunications device beyond the physical confines of the reflector. For example, where the reflector is a dish, the positioning means is configured so as to position the device beyond the rim of the dish. Reference is now made to Fig. 1 showing a preferred embodiment of the present system including a focussing reflector dish 10 mounted on a support arm 12. The support arm 12 is anchored into the substrate 14 by means of a buried concrete block (not shown). The system further comprises a platform 16 upon which a user 18 may stand. The platform is partially buried in the substrate 14 to prevent movement (the buried portion not shown in the drawing). Upon the platform 16 is a post 20, the post 20 being fixed securely into platform 16. Disposed upon the post 20 is a device support (cradle) 22 configured to retain a smart phone 24.

The device support is configured so as to angle the screen of the smart phone 24 toward the user 18, and to allow the unimpeded transmission of sound from the smart phone 24 speaker and also unimpeded reception of the user's voice into the smart phone 24 microphone.

In Fig. 1 , a cell phone transmission tower 26 is shown transmitting cell phone signal toward the reflector dish 10, as shown by the lines 28. The dish 10 is parabolic in cross section and configured to reflect the cell phone signal toward the cell phone 24, as shown by the lines 30. Intersection of the lines 30 is the focus point of the reflector dish 10. It will be noted that the cell phone is in a region at (or at least close to) the focus point.

Thus, the incoming cell phone signal 28 is focussed to a small region about the cell phone 24 thereby providing a higher strength signal and improving reception of the signal 28 from the tower 26.

When the smart phone 24 is transmitting a cell phone signal (not shown) the arrows on the lines 28 and 30 are reversed. In that circumstance, the reflector 10 acts to collimate the signal 30, and further acts as a directional antenna to direct the signal toward the tower 26.

It will be further noted that the system is configured such that the distance 32 between the reflector support 12 and the post 20 is fixed. In the arrangement of Fig. 1 , where the reflector dish 10 is about 1 .2 meters is diameter the range of the cell phone tower increased by a factor or at least about 1 .1 , 1 .2, 1 .3, 1 .4, 1 .5, 1 .6, 1 .7, 1 .8, 1 .9, 2.0, 2.1 , 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 or 3.0. Typically, a doubling of range is noted.

Fig. 2 shows an alternative arrangement whereby the smart phone mount 22 is disposed on an external wall of a building 34. In this embodiment, the user faces away from the reflector dish, and toward the building. Of course, any negative effect of the building and user on signal would need to be assessed.

Fig. 3 shows an alternative arrangement without a separate supporting post and whereby the smart phone mount 22 is disposed on the end of a member 36 extending directly from the reflector dish support 12. In this embodiment, the need to separately anchor a support post into the ground is avoided. Smart phones are very light, and so there is no requirement for the member 36 to have a substantial cross-sectional area.

Fig. 4 shows an alternative arrangement whereby the reflector dish 10 is disposed on an external wall of a building 34. In this arrangement, the building is unlikely to interfere with the signal given that the tower 26 is disposed behind the user.

Fig. 5 shows an alternative arrangement whereby the reflector dish 10 is disposed on an external wall of a building 34, and a rod 36 extends from the centre of reflector dish 10 so as to support the smart phone 24 in the focus region.

While the embodiments disclosed above a capable of useful improvements in gain (typically 5 to 15 dB), greater gains may be required. As will be appreciated, undulating terrain interposed between a cell phone tower and a reflector dish of the present system may diminish or even completely block transmission and/or reception of signal. This problem is typically overcome in the art by increasing the height of an antenna. However, in the present invention this approach is not practical since the antenna focus and hence the user would both have to be elevated by the same amount as the antenna.

One way to address that problem is to include in the system a waveguide configured to couple the elevated reflector to the cell phone. Such a design would require the use of large cross- section waveguide (around 250mm x 150mm) with feed horn end pieces. A further preferred option is to provide an elevated signal reflector which acts to capture signal from a position higher than the reflector dish, and reflect that signal downwardly to the reflector dish. The elevated reflector is disposed at the required height (as discussed further, infra), dimensioned, located and aligned to reflect the essentially horizontal beam to/from the cell phone tower down to the reflector dish which is typically facing 'backwards' and aimed upwardly at the reflector to direct the beam to a new focal point at the normal user height, located between the reflector and the dish.

In this case, the reflector dish is in the near field of the elevated reflector, and the electromagnetic behaviour of the pair is governed by near field equations. Such equations may be used to derive dimensions, distances, heights, orientations and the like for the reflector dish and the elevated reflector for a given application. With reference to the present invention the required reflector dimensions may be derived in a manner similar to that utilised in the electrical power industry to redirect SCADA (Supervisory Control and Data Acquisition) microwave telecommunications paths around terrain obstacles. Such methods are used for obstacles on a large scale, but are proposed to have some use in derivation of system parameters in the smaller scales of the present invention.

Reference is made to test cases 4 and 5 (as described in Example 5 herein) which applied these design principles and formulae, in such a way that with appropriate geometry and dimensioning, a given send-receive path utilising an intermediate passive repeater /reflector could achieve end-to-end signal transfer comparable in gain to a signal covering the same path between elevated end point equipment without the intermediate reflector. Alternative the above, given the benefit of the present specification the skilled person may utilize routine experimentation to configure any aspect of reflector dish or the elevated reflector.

As shown in the preferred embodiment of Fig. 6, a planar metallic reflector 50 is disposed in an elevated position by use of the support 52. The elevated reflector 50 is specifically angled so as to best intersect the incoming signal 28 so as to form a reflected signal 28A directed to the reflector dish 10. Alternatively, during transmission by the cell phone the signal firstly intercepts the dish 10 which reflects the signal to the elevated reflector 50, which in turn reflects the signal to the cell phone tower 26. By this arrangement, there is no requirement to elevate the reflector dish 10 and the user 18 in order to clear a geographic feature or a man- made structure so as to improve signal strength. The height of the parabolic dish is functionally increased without the need to physically elevate the dish, or indeed the user. Without wishing to be limited by theory in any way, it is proposed that for a given pair of cell phone tower and cell phone sites an average signal gain may be predicted by the following formula:

L ₀ = Lu - 4.78 {l goff -{- 18.33 Iog _I0 / - 40,94

where

Lv = 69.55 + 26.16 bg, _.0 / - 13.82 hg _m h _B - C _N + [44.9 - 6.55 io.g ₁₀ g _l0 d and

Cu = 0.8 + ( 1.1 hg _m f -- 0.7 } h. _M -- 1.56 bg _l0 / where / = frequency, h _M = height above ground level of the cell phone, h _B = height above ground level of the Radio Base Station (RBS) transceiver, and d = distance between the RBS and the cell phone.

At the frequencies of general use in regional and remote area mobile telephony in Australia and other countries (i.e. around 800-950 MHz), the formula predicts gains (i.e. reduction in the average path loss) as shown in Table 1 below.

Table 1 ; average relative path loss for varying cell phone heights above ground level.

Thus, the skilled person is enabled to derive an effective height required for a desired power gain. For example, elevating a parabolic dish from 2.3 meters to 4.5 meters yields a difference of 5.5dB. In many embodiments, useful gain increases will be obtainable whereby the elevated reflector is disposed at a height of at least about 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7,7.5, 8, 8.5, 9, 9.5 or 10 meters (as measured from the lowest edge of the reflector to the ground).

The elevated reflector 50 may be fabricated from any material which is capable of reflecting a mobile communication device signal, including any electrically conductive material such as a metal. Lightweight materials such as sheet metals are useful given the need for the reflector to be supported in an elevated position. As shown for the parabolic dish in Figs. 1 to 5, the reflector can be supported in an elevated position by way of a dedicated support structure (such as that marked 52 in Fig. 6) or by attachment to an existing structure such as a building. AS will be appreciated the angle of the reflector and the distance from the reflector to the reflector dish are important parameters which must be derived and set for each installation. Accordingly, it will be typical for the system to be constructed such that the distance between the 50 reflector and the reflector dish 10 are set. Once the distance is set, the angle of the reflector may be easily altered so as to best reflect the signal. The best angle may be derived theoretically, by means of a laser beam emitted from the tower, or by empirical means such as by measurement of signal strength by instrumentation having a receiving antenna disposed in the same position occupied by the cell phone.

Another method of increasing the strength of a signal is to provide a secondary reflector which opposes the reflector dish, the secondary reflector functioning to increase the directivity of the cell phone antenna with regard to the reflector dish. As will be appreciated, the means for increasing directivity may vary according to the type of antenna in the cell phone. In terms of general utility, a small planar metal plate reflector of the order of one wavelength by one wavelength placed behind a simple half wave dipole antenna (and without including the reflector dish in the signal path) theoretically yields a variable gain up to about 6dB, depending on the distance between the dipole and the reflector. The gain pattern is cyclic in nature because the phase of the reflected signal relative to the phase of the directly radiated / received signal causes it to either increase or decrease the signal amplitude. Where the distance is one half or a multiple of half wavelengths, this combined with the 180 degree phase change on reflection cancels the signal entirely (in theory) by destructive interference, while for odd multiples of a quarter wavelength the signal is increased by constructive interference. Such considerations may be taken into account in the design of a useful secondary reflector for any given application. In seeking to optimize gain, designing a secondary reflector for use in the present system requires a consideration of the cell phone antenna characteristics, which differ from the theoretical ideal dipole model and the effect of the reflector dish in focussing the signal. The dipole model assumes that the incoming/outgoing far field signal is a plane wave. The mechanical issue of mounting an inclined plate close to the cell phone support pedestal (marked as 22 in the drawings) without obstruction by the latter is also a consideration. Nevertheless, the flat plate sub-reflector is an appropriate model to test empirically, being simple to manufacture in a robust plate steel form. Typically, and as shown in Fig. 7, the secondary reflector 56 is relatively small, and opposed to the parabolic dish 10 with the cell phone 24 disposed a relatively short distance away from the secondary reflector 56. The secondary reflector is maintained in position by the support 58. As for the elevated reflector the secondary reflector 56 may be fabricated from any material which is capable of reflecting a mobile communication device signal. In terms of geometry, it may be substantially planar, curved (including parabolic), or be embodied as a corner reflector. The present system and methods for testing and operation thereof will now be provided by way of the following non-limiting examples.

EXAMPLE 1 : Materials and Protocols used in subsequent examples- Equipment and test facilities

Survey and test measurements of signal strength were obtained either through the use of a vehicle mounted test dish designed to set a test 1 .2m parabola at standard operating height (2.3m; a height which allows for comfortable use by an adult of average height) with a vehicle roof rack mounted extension to 4.7m. A trailer mounted version with the same capabilities, together with test phones and associated tools is also used.

For test cases 1 -9 (as further described infra), the following articles were fabricated or procured. a. A prototype 1 .7m x 1 .2m mirror reflector

b. A tripod stand and adaptors for field test mounting of the 1 .2m dish or signal generator and associated feed antenna at up to 2.3m Above Ground Level (AGL) c. A range of sub-reflector shapes and sizes d. A guyed pole with top platform to mount a laser and signal generator equipment at 4.5m AGL

e. A 1 .8m offset parabolic dish

f. An adapter to mount the 1 .8m dish on a trailer mount

For test easel 0 (as further described infra), the following articles are fabricated.

g. A prototype 2.2m x 2.0m mirror

h. A mount to support the 2.2m x 2.0m mirror at 4.5m AGL

i. A flange and pole to support the 1 .8m dish on a standard 1 .2m concrete slab

For the prototype integrated 1 .8m system

j. A stand-alone guyed pole mount for the 2.2m x 2.0m mirror

k. A modified slab incorporating tabs to house hold-down stakes

Signal source and measurement equipment

While some testing uses an actual Radio Base Station (RBS) tower and cell phone paired with the receiving equipment at a few tens of kilometres distance from the RBS to emulate real field conditions, other tests are more readily carried out using a locally accessible short range test bed with known fixed frequency signal generator (transmitter) and receiver.

For the latter purpose, a portable software controlled signal generator and spectrum analyser is used

Test range

In testing the present systems (including those requiring a local test range) it is preferred that the signal path and surroundings to be relatively distant from buildings, vegetation and any other objects that might reflect or absorb electromagnetic radiation. An open area of about 30 metres in line of sight from transmitter to receiver is preferred, and clear ground for about 50 metres in all directions around the signal path, and several hundred metres at either end of it.

Description of Test Cases

The overall development test regime was subdivided into a sequence of test cases which allow different components of the system to be characterized independently, to be followed by integrated testing of the whole system. The test cases are tabulated in Table 2.

Table 2; overview of test cases as described in the Examples. EXAMPLE 2: Test Case 1 - Configuration set-up: optimise feed antenna position

Reference is made to Figure 8, showing test case 1 . Antenna positioning was varied with fixed settings over a range of approximately 150mm to determine the best feed antenna to dish distance, and this position was locked in for subsequent tests.

EXAMPLE 3: Test Case 2 - Viability of spectrum analyser as a survey tool

Reference is made to Fig. 9, showing test case 2. While the test phone used in conjunction with the survey 1 .2m dish is generally reliable, the logistical requirements associated with the test trailer add time and cost to the process, and there may be some fluctuation in the received signal strength values (Receive Signal Code Power or RSCP) reported by the phone, necessitating the recording of a sample of 10-30 results in each instance, and averaging the results.

Tests were carried out at two locations to determine the viability of using the spectrum analyser in conjunction with a hand held reference antenna i.e. without the survey dish, as an alternative solution to the test phone plus trailer mounted dish configuration for field survey work. However, it was observed when testing the spectrum analyser plus hand held antenna alternative at the first site that the receive signal level varied considerably with the height above ground level (AGL) of the receiving antenna, by up to 13dB over a height range from 1 .2m to 2.3m AGL, the signal being stronger nearer to ground level (possibly due to ground reflections constructively interfering with the direct signal). Whilst a spectrum analyser may be useful as a survey tool, the variability of results may need to be considered in interpreting test data.

EXAMPLE 4: Test case 3 - test for height gain by spectrum analyser method.

Reference is made to Fig. 10. Measurements of changing signal strength with varying heights above the ground using a signal generator and spectrum analyser pair at short range may not be reliably extrapolated to real long distance (tens of kilometre) situations because of the effect of tower height, terrain and other variables. Accordingly, empirical testing using the signal from real RBS was pursued. Testing has been carried out at a number of central Australian locations at both the standard reflector dish height (2.3m AGL), and 4.5M AGL, in locations where sufficient signal was obtained at both heights to make a measurable comparison. Examples are presented in Table 3. These tests were carried out using either a smartphone in field test mode at the 1 .2m parabola focus measuring RSCP from the RBS, or using the spectrum analyser coupled with its own test feed antenna at the parabola focus, set to a reasonably wide receive bandwidth of 1 MHz to smooth some of the fluctuation in signal strength associated with changing RBS transmit power on individual channels.

Table 3; signal level gain with increased dish height (dB/m)

Old South 29/1 /16 SA -90 -92 +2

Road site 1

Old South 29/1 /16 SA -87 -89 +2 Road site 2

Old South 29/1 /16 Phone RSCP -96 RSCP -99 +3 Road site 2

Average +2.8 over all

tests

As can be seen from Table 3, the results were variable from location to location, time to time, and with the different test methods. The height gain was less than would be predicted, possibly because the predictor model assumes the cell phone device is stand-alone i.e. not coupled to a parabolic antenna.

Example 5: Verifying performance of passive repeater /dish combination (Test Cases 4 and 5)

Reference is made to Fig. 1 1 . The 1 .7m x 1 .2m mirror and 1 .2m dish equipment were positioned on the test range 30m apart to fit the required geometry as closely as possible, with the aim of fine tuning as necessary, as described below.

A low power green laser pointer simulating a transmitted radio beam was used to assist with alignment of the mirror/dish combination. The laser was mounted horizontally in the test range on a finely adjustable base mounted and fixed in turn to a small platform on the top of a guyed 4.5m aluminium pole at 30m from the receive end equipment. The mirror was mounted on the test trailer at the same height, and tilted down at the appropriate angle (in theory 22.5 degrees) to reflect the beam down at 45 degrees to the dish, which was mounted at a height above ground, angle of elevation, and horizontal distance from the reflector mounting point to set its focal point at the normal mobile user device height (1490mm). Note that the dish attitude in this scenario differs from that needed for the usual horizontal beam, being closer to ground level and angled upwards toward the mirror.

The first alignment step was to centre the laser beam at the mirror centre. To this end, a small optical mirror was glued to the mirror centre, to improve visibility from the laser end. Once this was achieved, the dish, mounted on a field tripod, was moved horizontally to centre the laser beam at the dish centre, where a further small optical mirror was placed. Finally, the dish elevation angle was adjusted to bring the laser beam to the dish focal point.

Results indicated that the dish mount needed adjusting 300mm forward and 120mm to one side from the initial position, and elevated upwards by 3 degrees to align the laser beam.

Reference is made to Fig. 12. Test case 5 was the actual end-to-end transmit receive test using the laser-aligned configuration. In addition to the correctly aligned test, the altitude and azimuth angles of the repeater / dish combination were subsequently varied to test sensitivity to minor mis-alignment errors. The test results are summarised in Table 4

Table 4; signal strength comparison - direct and reflected signal.

These results indicate that signal strengths for the two aligned configurations are in good agreement (within 1 dB) i.e. substituting a high mounted dish with a passive repeater / low mounted dish combination is equally effective, enabling a mobile device to be located suitably for a user standing at ground level and still gain the benefit of increased receive height.

As expected, introducing the passive repeater mirror increases the need for accurate alignment of all the elements. The results suggest that the mirror and dish need to be aligned within about +/ - 2 degrees and +/ - 5 degrees respectively of optimum to avoid losing appreciable height gain. For a customer installation, this implies that both mounts will require a mechanism for fine adjustment (typically threaded bolts on the mount heads) at the installation site.

EXAMPLE 6: Tests 6 and 7 - tests with small sub-reflector

Reference is made to Fig. 13 (test case 6) showing small sub-reflector initial test without dish. In order to characterise the general effect of a sub-reflector on signal gain at the frequencies of interest, Applicant first tested using a simplified receive-end configuration without the dish, consisting of a tuned dipole antenna connected to the spectrum analyser, with a rectangular flat plate reflector of dimensions 365mm x 325mm (approximately one wavelength by one wavelength i.e. λ by λ) mounted behind it i.e. on the far side of the dipole antenna away from the signal source.

The dipole receiving feed antenna was chosen because it has virtually no horizontal depth in the beam direction, enabling the distance to the reflector to be sharply defined. The signal generator (tuned to 923MHz in the ISM band), dipole antenna and reflector were all mounted at 1 .5m above the ground and approximately 1 .5m apart.

Figure 14 shows the variation in received signal strength with distance between dipole and reflector.

The sharp nulls at around 170mm, 340mm and 510mm correspond to half wavelength multiples where destructive interference occurs. The areas of practical interest are the flatfish peaks at odd multiples of λ/4 distance, around 90, 260 and 450mm where constructive interference occurs and gain is potentially increased.

Reference is now made to test case 7A (see Fig. 15), where the sub-reflector is used in combination with a dish. The sub-reflector was mounted on a graduated boom on a photographic tripod to enable the sub-reflector to be aligned such that the sub-reflector plane was orthogonal to the predicted beam direction from the 1 .2m dish to the receiving feed antenna (this beam direction below is referred to as the 'beam line') and moved in and out on the boom to vary the distance from the sub-reflector to the feed antenna (the dipole antenna or later the centre of the inbuilt phone antenna).

Testing was carried out at two sites initially (Mt Polhill and Tropic of Capricorn) using a dish height of 2.3m.

Results for the Tropic of Capricorn site are shown in Figure 15. The peaks and nulls are similar to the non-dish result, except that the peaks and nulls are shifted, indicating that by introducing the parabolic dish into the signal path some distortion of the interference pattern occurs.

Reference is now made to Fig. 17 showing test case 7B, whereby a cell phone replaces the dipole antenna and spectrum analyser of test case 7A. To emulate the real-life situation, the dipole and spectrum analyser were replaced with a test phone as receiver mounted in the normal way on the cradle. Because the phone has a horizontal depth in the beam direction of about 60mm in the normal configuration, some 'softening' of the signal strength pattern was expected.

The first set of tests using a phone as the receiving device were carried out at Mt Polhill using the λ by λ flat plate sub-reflector aligned at a beam angle of 46 degrees to the horizontal. The tests were repeated using a spherical section sub-reflector, located with its centre at the phone centre. In broad terms, the phone signal strength (RSCP) in both cases varied with sub- reflector to phone distance consistent with the pattern exhibited by the dipole antenna + signal generator + spectrum analyser configuration (without the dish) first described, though with a less pronounced peak -null pattern.

At the Tropic of Capricorn site, the rectangular sub-reflector size was varied, again with the phone as receiving device. RSCP measurements were compared for flat plate sub-reflectors of λ by λ, and ½ λ by ½ λ ( for example, 190mm x 150mm) dimensions. The ½ λ by ½ λ sub- reflector was more compact, enabling it to be moved closer to the phone at higher gain without being obstructed by the cradle pedestal. The closest distance that can be achieved mechanically for a small ½ λ x ½ λ sub-reflector without this obstruction is approximately 100mm (and correspondingly greater distances for larger sub-reflectors).

Figure 15 shows results for the λ x λ and ½ λ x ½ λ sub-reflector sizes.

The skilled person will appreciate there may be some variability in results for different phone types where the sub-reflector is located at very close proximity to the phone itself, given that the near field region boundary of the phone's antenna may be in the order of 80mm from the phone, and behaviour within the near field region may be more dependent on the phone antenna design. Thus different phones might have varying antenna characteristics and not necessarily be equally advantaged by a single sub-reflector design.

A minimum sub-reflector distance of about 100mm may provide results that would be advantageous (and possibly even consistently advantageous) for most phones.

Another consideration influencing the size and placement of the reflector is that for a small ½ λ x ½ λ reflector at around 100-150mm distance from the phone centre, the gain is high, but also variable with distance (Figure 18). Thus some users might obtain quite different results than others depending on phone (including tablet) type and where the device is positioned on the cradle. Thus a conservative design utilising the flatter ¾ λ peak may provide more consistent results across multiple device types.

The configuration was further refined in a number of steps, using a sub-reflector of an intermediate size of ¾ λ by ¾ λ, and varying the altitude angle of the sub-reflector axis, since the actual angle of the beam line from the dish was not precisely known:

36 degrees from horizontal, corresponding with a line joining the phone centre with the centre of the swept area of the dish

43 degrees from horizontal (intermediate)

51 degrees from horizontal, corresponding with a line joining the phone centre with the dish physical centre

The slightly stronger peak RSCP readings were measured with the 36 degree setting, so that parameter was fixed in all subsequent tests (Figure 16).

For confirmation, the tests were repeated at Simpsons Gap. At this site, a lesser amount of gain in signal strength was obtained with the sub-reflector at the beam line than that determined at the Tropic of Capricorn, although it was found that by repositioning the sub- reflector below the predicted beam line, the gain at around ¾ λ from the phone centre became comparable with the gain achieved at the Tropic of Capricorn site. This motivated a modification to the testing regime, by designing a jig to allow subsequent gain measurements to be expanded into two dimensions by varying both the sub-reflector plane distance from the phone centre and through a range of positions above and below the predicted beam line.

Spreadsheet plots of these measurements were prepared for other field sites as they were commissioned. The Tropic and Aileron sites gave maximum gain with the sub-reflector at or near the beam line, while Simpsons Gap and Stuart Memorial gave better gain with the sub- reflector below the beam line.

Table 5 shows the gain in average peak signal strength measured with the test phone and optimally located sub-reflector at several test sites, relative to the average signal strength at that site without the sub-reflector.

Table 5; optimal sub-reflector gain for several sites

Overall, the results indicate that a gain of around 3dB to 5dB can be achieved using this configuration, provided the site variations are taken into account in mounting the sub reflector. Accordingly, the mount for the sub-reflector may need to be designed to allow these variations to be set at installation time on an individual site basis.

EXAMPLE 7: test case 8 using larger parabolic antenna

For implementation purposes, an increase from d=1 .2m to 1 .8m appeared to be the largest justifiable in terms of the impact on equipment, mounting and logistic costs, giving an increase in area and hence of predicted gain of 2.25 times or 3.5dB. Test case 8 was designed to confirm the increased gain.

This test was conducted at the Tropic of Capricorn site, using a test phone at the focus of a 1 .8m dish mounted on the test trailer, and comparing signal strength with the signal received by the same phone when mounted on the installed 1 .2m dish. Table 6 shows the results.

Table 6; signal strength variation with dish size

The 1 .8m result is within 1 dB of (and slightly better than) the theoretical prediction. A secondary factor associated with increasing the size of the parabola is that the beamwidth becomes narrower, necessitating increased care in aiming the parabola at the RBS, and also in locating the smartphone at the antenna focus.

Beam width is given by

Θ = kX/d

Where Θ, the beam width in degrees, decreases inversely with the increase in antenna diameter d . EXAMPLE 8: test case 9 - integration test

Integration testing was performed at the Garden Road / Stuart Highway intersection with the 1 .7m x 1 .2m passive repeater mirror at 4.6m AGL using a low mounted 1 .2m dish directed upward to the mirror at a 45 degree beam angle. The RBS in this case was the West Gap RBS. The ¾ λ x ¾ λ sub reflector was used. The variation of received signal strength with differing sub-reflector to phone distances is shown in Fig 17, demonstrating that signal strength was relatively constant for distance variations between about 220mm and 260mm. The peak gain results from this test are summarised in Table 7.

Table 7; optimal sub-reflector gain - integrated test with 1.2m parabola and passive reflector at 4.6m AGL

Comparing these results with those from tests conducted earlier at the same location with a 1 .2m parabola mounted at the same elevated height (test case 3, Table 3: -1 14.5 dBm) indicates a dramatically improved result for the configuration without the sub-reflector. Since such a result would not normally be expected, much of the difference may be attributed to a positive change in the transmission conditions, whether due to time of day, weather, or RBS traffic loading. Nevertheless, the integration test result is confirmation that introducing an appropriately positioned sub-reflector into this configuration provides a further gain comparable to that achieved in the stand-alone tests (test case 7).

A more realistic and conservative estimate of the aggregate gain to be expected from combining all the development elements together is given in Table 8.

Table 8; estimate of aggregate gain from system having higher and larger dish compared to smaller and lower dish

^* applicable in locations where positive height gain is available Returning to the formula for path loss in open areas:

La = Lv - 4,78 (fo¾ _€ f + 18.33 log» / - 40.94

where

Lis — 69.55 + 26.16 log _t0 /— 13.82 log ₁₀ h _& — C¾ + [44.9— 6.55 log ₁₀ lag^ d

The gain required to overcome the additional path loss for a location at say double the distance d from the base station is dependent on the height of the base station antenna h _B (in metres), i.e. the gain required = (44.9 - 6.55 Iog10 h _B ) logl 0 (di/d ₂ )

For a typical h _B of 30 metres, and d2 = 2di

Gain = -(44.9 - 6.55 log 10 h _B ) log 10 (di/d ₂ )

= -35.2 x -0.30

= 10.5 dB

This gain figure is relatively insensitive to h _B , ranging from 10.9 dB at h _B = 20m to 10.1 dB at h _B = 50 metres.

Thus the theoretical gain required to double the transmission range for a mobile signal is around 10 to 1 1 dB, and the three part integrated solution as described in this report should give a reasonable level of confidence that the increasing the effective height of the dish can achieve this, noting that in individual cases there may be variability (up or down) in this figure due to terrain and other local variables.

EXAMPLE 9: test case 10 - Integration testing with1.8m parabolic reflector.

Because of the logistic complexity in mounting an equivalent configuration for a field based integration test using a 2.2m x 2.0m passive repeater and 1 .8m parabola, the latter is tested in conjunction with the prototype installations described in the preceding Examples.

An advantage of the present invention is that it may be completely passive; i.e. require no electricity for operation. However, some embodiments may comprise active signal amplification means so as to further improve operating range. For example, a receiving antenna may be disposed in the position normally occupied by the cell phone, with the receiving antenna feeding signal to a powered amplifier. The amplified signal may be transmitted wirelessly to the user's cell phone via the normal cell phone signal receiving antenna or via WiFi™, Bluetooth™ or Ant™ (where permitted by local regulations or laws) or by wired connection. Given the likely remote location of the system, the amplifier will typically consume relatively low power and may be configured to operate for extended periods on solar power, optionally with a rechargeable battery connected thereto. Alternatively, the amplifier may be operable by way of human actuatable generator (such as a hand cranked dynamo), or a 12V vehicle battery While the embodiments shown in the drawings are directed to substantially fixed systems, it is contemplated that the present invention is applicable to portable systems. For example, collapsible/folding reflector antennas are known in the art will be adaptable for use with the present invention. Heavy duty foldable antennas are provided by Antenna Research Associates Inc (Beltsville MD). Lighter duty antennas that may be amenable for use by users camping in remote areas are also known, an exemplary form being disclosed in United States Patents 4,527,166; and 4,608,571 the contents of each patent specification are herein incorporated by reference.

The present invention has been disclosed mainly in regards to cell phone systems, this being an area of main utility of the invention. It will be appreciated, however, that given the benefit of the present specification, the invention can be applied to other mobile communication systems such as two-way radio, satellite telephone systems and the like.