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Title:
METHOD AND SYSTEM FOR IN-BUILDING DISTRIBUTION OF INFORMATION
Document Type and Number:
WIPO Patent Application WO/2017/171914
Kind Code:
A1
Abstract:
A retransmission device includes an outdoor receiver and a modulation circuit. The outdoor receiver receives a wireless signal. The wireless signal includes relevant information. The modulation circuit includes circuitry that generates a modulated signal bearing the relevant information and that outputs the modulated signal to a redistribution system.

Inventors:
RYAN DAVID J (US)
Application Number:
PCT/US2016/050231
Publication Date:
October 05, 2017
Filing Date:
September 02, 2016
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
NOKIA SOLUTIONS & NETWORKS OY (FI)
RYAN DAVID J (US)
International Classes:
H04B3/54; H04L12/28; H04W4/18
Foreign References:
US6243571B12001-06-05
US6411926B12002-06-25
US20100296499A12010-11-25
Attorney, Agent or Firm:
RAUDEBAUGH, Kevin W. (US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A retransmission device, comprising:

an outdoor receiver that receives a wireless signal, the wireless signal including relevant information; and

a modulation circuit including circuitry that generates a modulated signal bearing the relevant information and that outputs the modulated signal to a redistribution system.

2. The retransmission device of claim 1, further comprising: a processor that extracts the relevant information from the wireless signal and that causes the modulation circuit to generate the modulated signal.

3. The retransmission device of claim 1, wherein the redistribution system includes a mains power line, and the modulation circuit outputs the modulated signal over the mains power line.

4. The retransmission device of claim 3, wherein the modulated signal is a power line communication (PLC) signal.

5. The retransmission device of claim 1, wherein the redistribution system includes a wireless local area network (WLAN) transmitter, and the modulation circuit outputs the modulated signal to the WLAN transmitter.

6. The retransmission device of claim 1, wherein the relevant information includes any of a timing reference, a frequency reference, and location information.

7. The retransmission device of claim 6, wherein the modulation circuit outputs the modulated signal to an indoor device over the redistribution system, the indoor device being a femtocell.

8. The transmission device of claim 7, wherein the wireless signal is a global positioning system (GPS) signal, and the relevant information includes a timing reference.

9. A signal redistribution system, comprising:

a modulator circuit that generates a modulated signal, and that transmits the modulated signal to a redistribution system, the modulated signal including relevant information; and

a demodulator circuit that receives the modulated signal from the redistribution system, that extracts the relevant information from the modulated signal, and that transmits the extracted relevant information to an indoor electronic device.

10. The signal redistribution system of claim 9, further comprising processor that extracts the relevant information from a wireless signal and that causes modulator circuit to generate the modulated signal.

1 1. The signal redistribution system of claim 9, wherein the redistribution system includes a mains power line, and the modulator transmits the modulated signal over the mains power line.

12. The signal redistribution system of claim 9, further comprising:

an outdoor receiver coupled to the modulator, the outdoor receiver receiving a wireless signal including the relevant information, the relevant information including any of a timing reference and a frequency reference, and

wherein the indoor device is a femtocell coupled to the demodulator.

13. A redistribution method, comprising:

receiving, by an outdoor receiver, a first signal;

extracting, by a processor, relevant information from the first signal; and outputting, to an indoor device, by a modulator circuit, a second signal including the relevant information.

14. The redistribution method of claim 15, wherein outputting the second signal includes superimposing the second signal on a power supply voltage over a mains power line.

15. The redistribution method of claim 14, wherein the second signal is a power line communication (PLC) signal.

16. The redistribution method of claim 13, wherein outputting the second signal includes outputting the second signal to a wireless local area network (WLAN) transmitter, the WLAN transmitter being in wireless communication with the indoor device.

17. The redistribution method of claim 13, wherein the relevant information includes any of a timing reference, a frequency reference, and location information.

18. The method of claim 17, wherein the wireless signal is a global positioning system (GPS) signal, and the relevant information includes a timing reference.

Description:
METHOD AND SYSTEM FOR IN-BUILDING DISTRIBUTION OF

INFORMATION

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Patent Application No. 15/085,933, filed on March 30, 2016, which claims priority to U.S. Provisional Patent Application No. 62/140,208, filed on March 30, 2015, U.S. Provisional Patent Application No. 62/140,195, filed on March 30, 2015, U.S. Provisional Patent Application No. 62/140,212, filed on March 30, 2015 and U.S. Provisional Patent Application No. 62/140,217, filed on March 30, 2015, each of which are incorporated by reference herein for all purposes.

BACKGROUND

[0002] Field of Invention

[0003] Embodiments relate to the field of computer networks and communications over computer networks, including communications over wireless networks, and relate to retransmitting information from a wireless signal to an indoor device through a redistribution system.

[0004] Background Art

[0005] Many electronic devices require or benefit from highly accurate synchronized timing, frequency, and or location information. Examples of such electronic devices include in- building wireless networking equipment, such as wireless femtocells supporting commercial cellular or personal communications service (PCS) bands. For example, wireless femtocells typically require high levels of network timing synchronization (e.g., to sub microsecond levels) in order to minimize interference across the wireless network and to support mobility functions such as signal handover to neighboring base stations.

[0006] Some electronic devices, such as femtocells and other types of base stations, transmit signals in a coordinated matter using techniques such as orthogonal frequency division multiplexing (OFDM). In an OFDM scheme, devices are assigned different time and frequency bands in order to prevent interference between signals transmitted from different devices. The devices must use highly accurate timing and frequency synchronization information in order to efficiently utilize the OFDM scheme. [0007] Many of these devices also require accurate knowledge of the geographic location of each wireless base station to support network optimization and to support emergency calling, e.g., Emergency 911 (E911), requirements.

[0008] Examples of other devices that would benefit from accurate indoor time and frequency information include any consumer electronics equipment with a time of day clock. With accurate time and frequency information, such equipment could automatically synchronize the clock with regional and national standards, rather than relying on consumers to individually set the clock.

[0009] Devices can obtain timing, frequency, and location information using a variety of existing methods. For example, the devices can acquire the information over outdoor wireless networks using outdoor electronics equipment. Specifically, wireless global positioning system (GPS) satellite signals provide highly accurate time, frequency and location information through commonly available receiving equipment. The information obtained from GPS signals can be locally distributed over proprietary networks. For example, the information can be broadcast from outdoor cell sites for the purpose of synchronizing nearby cells.

[0010] However, many existing systems that share timing, frequency, and location information broadcast at high radio frequencies, and/or transmit signals with relatively low signal strengths, so the signals broadcast by existing systems are highly attenuated by buildings or structures. Femtocells and other equipment located within underground parking garages, subway stops, hospitals, and other buildings cannot reliably receive signal broadcast at high frequencies and low signal strength. Accordingly, indoor devices and equipment cannot reliably receive information directly from outdoor base stations and other outdoor wireless broadcast sources due to signal loss from the surrounding buildings or structures.

[0011] Some indoor devices can acquire timing, frequency, and location information over the Internet. For example, rather than relying on information from outdoor GPS signals, the devices can access timing, frequency, and location information from a different Internet- based source. The devices, however, can only receive information over the Internet after a significant time delay, e.g., greater than one millisecond. Accordingly, acquiring timing and frequency information directly over the Internet is not suitable when the device requires very accurate timing and frequency references, e.g., references accurate to the nearest millisecond or less. [0012] Devices can also use so-called "indoor GPS" systems to acquire information. However, indoor GPS systems are prohibitively expensive for many commercial and residential consumers. Furthermore, even indoor GPS systems do not provide the necessary reliability across a wide range of building types or into certain indoor spaces such as tunnels and underground structures, or other poor satellite signal quality environments.

BRIEF SUMMARY OF THE DISCLOSURE

[0013] Embodiments of this disclosure relate to providing relevant information (e.g., accurate timing, frequency, and or location information) to electronic equipment operating inside of buildings, underground or otherwise unable to directly access signals bearing the relevant information.

[0014] In an embodiment, a receiver is placed outdoors where sufficient radio frequency signal strength is present without the additional losses associated with radio frequency signal penetrating buildings. This highly reliable, externally received information is then retransmitted into the building or structure via low power methods, such that the information is localized to the building of interest.

[0015] A retransmission device may include an outdoor receiver that receives a wireless signal and a modulation circuit. The wireless signal may include relevant information. The modulation circuit may include circuitry that generates a modulated signal bearing the relevant information and that outputs the modulated signal to a redistribution system.

[0016] The retransmission device may further include a processor that extracts the relevant information from the wireless signal and that causes the modulation circuit to generate the modulated signal.

[0017] The redistribution system may include a mains power line, and the modulation circuit may output the modulated signal over the mains power line.

[0018] The modulated signal may be a power line communication (PLC) signal.

[0019] The redistribution system may include a wireless local area network (WLAN) transmitter, and the modulation circuit may output the modulated signal to the WLAN transmitter. [0020] The relevant information may include any of a timing reference, a frequency reference, and location information.

[0021] The modulation circuit may output the modulated signal to an indoor device over the redistribution system. The indoor device may be a femtocell.

[0022] The wireless signal may be a global positioning system (GPS) signal, and the relevant information may include a timing reference.

[0023] A signal redistribution system may include a modulator circuit and a demodulator circuit. The modulated circuit may generate a modulated signal and transmit the modulated signal to a redistribution system. The modulated signal may include relevant information. The demodulator circuit may receive the modulated signal from the redistribution system, extract the relevant information from the modulated signal, and transmit the extracted relevant information to an indoor electronic device.

[0024] The signal redistribution system may further include a processor that extracts the relevant information from a wireless signal and that causes the modulator circuit to generate the modulated signal.

[0025] The redistribution system may include a mains power line, and the modulator may transmit the modulated signal over the mains power line.

[0026] The signal redistribution system may further include an outdoor receiver coupled to the modulator. The outdoor receiver may receive a wireless signal including the relevant information. The relevant information may include any of a timing reference and a frequency reference. The indoor device may be a femtocell coupled to the demodulator.

[0027] A redistribution method may include receiving, by an outdoor receiver, a first signal; extracting, by a processor, relevant information from the first signal; and outputting, to an indoor device, by a modulator circuit, a second signal including the relevant information.

[0028] Outputting the second signal may include superimposing the second signal on a power supply voltage over a mains power line.

[0029] The second signal may be a PLC signal.

[0030] Outputting the second signal may include outputting the second signal to a WLAN transmitter. The WLAN transmitter may be in wireless communication with the indoor device. [0031] The relevant information may include any of a timing reference, a frequency reference, and location information.

[0032] The wireless signal may be a GPS signal, and the relevant information may include a timing reference.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 illustrates wireless communications system according to an embodiment.

[0034] FIG. 2 illustrates a system, which modulates a signal onto a retransmission system for use by devices located inside of a building, according to an embodiment.

[0035] FIG. 3 illustrates a retransmission device, according to an embodiment.

[0036] FIG. 4 illustrates a demodulator, according to an embodiment.

[0037] FIG. 5 illustrates a system receiving a GPS signal and distributing information from the GPS signal through indoor electrical wiring, according to an embodiment.

[0038] FIG. 6 illustrates a system receiving GPS signal and distributing information from the GPS signal through an indoor wireless network, according to an embodiment.

[0039] FIG. 7 illustrates a system receiving regional network signals via a proprietary wireless network and distributing information from the network signal through indoor electrical wiring, according to an embodiment.

[0040] FIG. 8 illustrates a process for modulating a wireless signal and outputting relevant information from the wireless signal to a redistribution system, according to an embodiment.

[0041] FIG. 9 illustrates a process for receiving a signal from a redistribution system, according to an embodiment.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0042] A detailed description of embodiments is provided below along with accompanying figures. The scope of this disclosure is limited only by the claims and encompasses numerous alternatives, modifications and equivalents. Although steps of various processes are presented in a particular order, embodiments are not necessarily limited to being performed in the listed order. In some embodiments, certain operations may be performed simultaneously, in an order other than the described order, or not performed at all. [0043] Numerous specific details are set forth in the following description in order to provide a thorough understanding. These details are provided for the purpose of example and embodiments may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to this disclosure has not been described in detail so that the disclosure is not unnecessarily obscured.

[0044] This disclosure provides a method for receiving information via receiving equipment located outside of a building and redistributing those signals to equipment located inside of the building.

[0045] Embodiments may include three main components: (1) An external radio frequency receiver compatible with regional or global synchronization information such as GPS or proprietary synchronization transmission; (2) circuitry that isolates a pertinent synchronization signal such as timing, frequency, and/or location information and remodulates that information onto suitable local redistribution system such as building power lines, a local wireless local area network (WLAN) transmitter, or through a proprietary retransmission scheme; and (3) circuitry incorporated into indoor electronics equipment to receive synchronization information for use by the electronics equipment.

[0046] Embodiments include utilizing externally mounted GPS receivers with a clear view of the sky receiving timing, frequency and location information from GPS satellites. The information is modulated by a signal modulator coupled to a local retransmission system, such as the building's power wiring. The signal modulator transmits the modulated information through the local retransmission system, which distributes the information throughout the indoor space.

[0047] For example, when the local retransmission system is an indoor power line, the signal modulator may transmit the modulated information by changing the voltage levels of the indoor power line. Accordingly, electronic devices or equipment using the indoor power line as a power supply can receive the relevant information from power cabling. That is, electronics equipment located within the building equipped with compatible demodulator circuitry, which is coupled to the power line, can receive the relevant information from power cabling.

[0048] The frequency, timing and location information transmitted over the internal power line wiring can be in a different format than the GPS signal itself. The modulator can be used to change the format of the GPS signal before transmitting the information through the local retransmission system.

[0049] Alternatively, other retransmission schemes are possible. In embodiments, the information can be retransmitted locally over relatively low power transmitters operating, for example, in unlicensed (by the Federal Communications Commission, or other regional authorities) frequency bands or via unlicensed Wi-Fi (e.g., IEEE 802.11) networks. In these cases, the closer the local retransmission system is to the end point electronics equipment receivers, the higher the reliability is for the information received by the end point electronics equipment.

[0050] Embodiments of this disclosure are not limited to retransmission of a GPS signal. In addition to a GPS signal, a regionally distributed information signal can be retransmitted to in-building equipment using some embodiments, with the same benefits of increasing reception reliability and overcoming signal degradation to in-building equipment.

[0051] FIG. 1 illustrates a wireless communications network 100 according to an embodiment. The wireless communications network 100 includes an outdoor base station 110, a first user equipment (UE) 120, an indoor base station 140, a second UE 150, a retransmission device 160, and a satellite 170.

[0052] The outdoor base station 110 may transmit and receive signals from various devices in a surrounding cell 112 via one or more antennas installed on the outdoor base station 110. The outdoor base station 110 may have an antenna that is a receive antenna which may be referred to as a receiver, and a transmit antenna, which may be referred to as a transmitter. As used herein, the term "base station" refers to a wireless communications station provided in a location and serves as a hub of a wireless network. For example, in LTE, a base station may be an eNodeB. The base stations may provide service for macrocells, microcells, picocells, or femtocells. In other embodiments, the base station may be an access point in a Wi-Fi network. Although FIG. 1 illustrates a single outdoor base station 110, embodiments are not limited thereto.

[0053] The first UE 120 may be located within the cell 112, and may be in communication with the outdoor base station 110. As used herein, the term "UE" may include cell phone devices, laptop computers, handheld gaming units, electronic book devices and tablet PCs, and any other type of common portable wireless computing device that may be provided with wireless communications service. The wireless communications service may employ any common wireless data communications technology, including, but not limited to: GSM, UMTS, 3GPP LTE, LTE Advanced, WiMAX, etc.

[0054] The indoor base station 140 may be located inside of a building 130. The building 130 may be a residential home, a hospital, a parking garage, or any space shielded from the outdoor base station 110 by walls or other structures. The indoor base station 140 may transmit and receive signals in a cell located within the building 130.

[0055] The indoor base station 140 may coordinate with the outdoor base station 110. The indoor base station 140 may use information, such as timing and/or frequency information, in order to synchronize with the outdoor base station 110. For example, the outdoor base station 110 and the indoor base station 140 may transmit and/or receive signals according to an OFDM scheme. However, the building 130 may prevent the indoor base station 140 from deriving accurate timing and/or frequency information from a wireless signal broadcast outside of the building 130. Accordingly, the building 130 may prevent the indoor base station 140 from synchronizing with the outdoor base station 110 on the basis of outdoor wireless signals alone.

[0056] The second UE 150 may be located within the building 130, and may be in communication with the indoor base station 140. The second UE 150 may be a mobile device, and may move from inside the building 130 to outside of the building 130, thereby triggering a coordinated handoff operation when the second UE 150 enters the cell 112.

[0057] The retransmission device 160 may therefore act as a liaison between an external transmitter broadcasting synchronization information and the indoor base station 140. The retransmission device 160 may retransmit information in a wireless signal received outside of the building 130 to the indoor base station 140 using an indoor redistribution system. The retransmission device 160 may include a receiver that receives a wireless signal from the satellite 170. In an embodiment, the wireless signal is a GPS signal containing timing, frequency, and location information, and the satellite 170 is a GPS satellite.

[0058] The retransmission device 160 may extract relevant information from the wireless signal, and then retransmit the relevant information by outputting a modulated signal including the extracted relevant information to a retransmission system inside the building 130. The modulated signal may have a different format than the wireless signal received from the satellite 170. The indoor base station 140 may be coupled to the retransmission system, such that the indoor base station 140 may receive the modulated signal from the retransmission device 160. Accordingly, the relevant information from the wireless signal can be rapidly, accurately, and reliably transmitted to the indoor base station 140.

[0059] The indoor base station 140 may be coupled to a demodulator that can isolate the relevant information from the modulated signal. In an embodiment, the demodulator may be integrated into the electronics of the indoor base station 140, or may be a separate, removable device that can be selectively coupled to the indoor base station 140.

[0060] The indoor base station 140 may, for example, transmit a signal in a designated OFDM resource block by referencing an objective timing and/or frequency reference shared by the outdoor base station 110. The objective timing reference may be transmitted to the modulator from a GPS satellite. The retransmission device 160 may transmit the objective reference to the indoor base station 140 through the indoor retransmission system. Accordingly, the outdoor base station 110 and the indoor base station 140 may be synchronized.

[0061] FIG. 2 illustrates a system 200, which modulates a signal onto a retransmission system for use by devices located inside of a building, according to an embodiment. In an embodiment, the system 200 may distribute signals throughout the retransmission system by transmitting low voltage differential signals through electrical wiring in the building. The wiring may be a mains power line or a phone line.

[0062] The system 200 may include a retransmission device 210 and a demodulator 250.

[0063] The retransmission device 210 may include a receiver 212 and a modulator 214. In an embodiment, the retransmission device 210 may include other components, such as a processor and a memory, as well as other digital and/or analog circuitry. In an embodiment, the receiver 212 may be separated from the retransmission device 210.

[0064] The receiver 212 may receive a wireless signal that includes relevant information. The wireless signal may be transmitted from a remote transmitter, such as a satellite transmitter. The wireless signal may be a GPS signal received from a remote GPS satellite. In an embodiment, the wireless signal is a wireless signal received from a proprietary wireless network, and may include regional network timing information.

[0065] The receiver 212 may be an outdoor receiver, that is, located outside of a building. In an embodiment, the receiver 212 may be attached to a roof or an exterior wall 242 of the building. Accordingly, the receiver 212 may receive the wireless signal from a remote outdoor source with minimal to no attenuation and/or interference by the building.

[0066] In an embodiment, the relevant information includes any of timing, frequency, and location information. The timing information may indicate a current time with a high degree of accuracy. The timing information may be, for example, a 1 pulse per second timing reference. The frequency information may include a frequency reference based on a nearby network. The location information may be used to derive a latitude, longitude, and/or altitude of the receiver 212.

[0067] The modulator 214 may include digital and/or analog circuitry that performs specific modulation functions. In an embodiment, the modulator 214 extracts the relevant information from the wireless signal, and embeds the relevant information into a modulated signal 236. In another embodiment, separate circuitry (e.g., a separate processor) may extract the relevant information from the wireless signal, and cause the modulator 214 to retransmit the relevant information in the modulated signal 236.

[0068] The modulated signal 236 may include the relevant information, and may be in a different format than the received wireless signal. For example, the modulated signal 236 may be a power line communication (PLC) signal. The modulated signal 236 may be any of a broadband or narrowband PLC signal.

[0069] The modulator 214 of the retransmission device 210 may be coupled to the mains power line 230. The modulator 214 may output the modulated signal 236 to the mains power line 230. The modulator 214 may output the modulated signal 236 to the mains power line 230 using, for example, a PLC protocol. Example PLC protocols include Universal Powerline Bus, X10, and LonTalk. The modulator 214 may include a PLC modem that may output the modulated signal 236, and be connected to an additional power supply.

[0070] The mains power line 230 may include a first line 232a, a second line 232b, an exterior outlet 234, and an interior outlet 240. Each of the first and second lines 232a and 232b may include a hot wire and a neutral wire. In an embodiment, each of the first and second lines 232a and 232b additionally includes a ground wire. Accordingly, each of the first line 232a and the second line 232b may carry a voltage between the hot wire and the neutral wire. [0071] The first and second lines 232a and 232b may carry the modulated signal 236 superimposed with a power supply voltage. The power supply voltage may be used to power devices, such as the electronic device 260, connected to the mains power line 230. In a specific embodiment, the power is an alternating current (AC) with a voltage of 120V and a frequency of 60 Hz. In another embodiment, the power supply voltage is a direct current (DC) signal.

[0072] Each of the first and second lines 232a and 232b may additionally carry the modulated signal 236. That is, the modulator 214 may superimpose the modulated signal 236 with the power supply voltage over the first and second lines 232a and 232b.

[0073] The modulated signal 236 may have a low voltage and a high frequency, such that power supply circuits attached to the first and second lines 232a and 232b may filter or otherwise ignore the modulated signal 236 as noise. That is, the modulated signal 236 may be in a noise range of a power supply circuit 262 of the electronic device 260, and the modulated signal 236 may not impact the utilization of the power supply voltage by the devices coupled to the mains power line 230. For example, the modulated signal 236 may have a voltage of less than 3 mV and a frequency of greater than 30 kHz.

[0074] The first and second lines 232a and 232b may be embedded within the walls of the building, and may each be coupled to the exterior outlet 234 and the interior outlet 240. The first and second lines 232a and 232b may be located between an exterior wall 242 and an interior wall 244 of the building. The exterior outlet 234 is coupled to the modulator 214 of the retransmission device 210. The interior outlet 240 is coupled to the demodulator 250 and the electronic device 260. In an embodiment, the retransmission device 210, the demodulator 250, and the electronic device 260 are powered by the power supply voltage distributed by the mains power line 230.

[0075] The demodulator 250 may isolate the modulated signal 236 from the superimposed voltage transmitted through the first and second power lines 230a and 230b, and may extract the relevant information from the modulated signal 236 for use by the electronic device 260. In an embodiment, the demodulator 250 filters the modulated signal 236 from the superimposed voltage distributed by the first and second power lines 230a and 230b, extracts the relevant information from the modulated signal 236, and then outputs the relevant information to the electronic device 260. In an embodiment, the demodulator 250 is a PLC modem. [0076] Although FIG. 2 shows the demodulator 250 integrated into the electronic device 260, in other embodiments the demodulator 250 may be a part of a separate device coupled to the interior outlet 240 that transmits the demodulated signal, or information derived from the demodulated signal, to the electronic device 260. The demodulator 250 may be a modular attachment that can be disconnected from the interior outlet 240 and/or the electronic device 260.

[0077] The electronic device 260 may include a power supply circuit 262 coupled to the first and second power lines 230a and 230b that provides power to the electronic device 260.

[0078] In an embodiment, the power supply circuit 262 may filter the modulated signal 236 from the power lines using an analog and/or digital filter, and may supply power to circuitry in the electronic device 260. In another embodiment, the modulated signal may be in a noise range of the power supply circuit 262, such that the power supply circuit 262 and other circuitry in the electronic device 260 may utilize the power supply voltage and ignore the modulated signal.

[0079] The electronic device 260 may therefore be powered by the mains power line 230 and may receive the relevant information from the demodulator 250. Accordingly, the electronic device 260 may receive the relevant information from the wireless signal indirectly over existing structures in the building, even when the electronic device 260 is unable to receive the wireless signal directly.

[0080] In an embodiment, the electronic device 260 includes a clock display, the relevant information is objective timing information, and the electronic device 260 uses the timing information to correct a time kept by the clock display. The electronic device 260 may be a recorder coupled to a cable box, and the relevant information may be timing information. The recorder may use the timing information to trigger recordings of television programs received by the cable box at predetermined times.

[0081] In an embodiment, the electronic device 260 is an indoor base station, and the relevant information is any of timing, frequency, and location information. The relevant information may be a timing and/or frequency reference corresponding to a nearby network. The indoor base station may use the timing and/or frequency reference to synchronize transmissions and handovers with other elements of a telecommunications network, which may include macro- cell base stations located outside of the building. [0082] FIG. 3 illustrates a retransmission device 300, according to an embodiment. The retransmission device 300 may include a receiver 310, an analog-to-digital converter (ADC) 320, a system bus 330, a memory 332, a processor 334, a user interface 336, and a modulator circuit 340. The retransmission device 300 may be the retransmission device 210 of FIG. 2.

[0083] The receiver 310 may receive a wireless signal from a remote transmitter. In an embodiment, the wireless signal is a GPS signal received from a remote GPS satellite. In another embodiment, the wireless signal is received from a proprietary wireless network, and may include regional network timing information.

[0084] The wireless signal may include relevant information, which can be utilized by an indoor electronic device. In embodiment, the relevant information includes one or more of timing information, frequency information, and location information. The timing information may include a timing reference indicating a current time with a high degree of accuracy. The frequency information may include frequency reference indicating synchronization information utilized by a nearby network.

[0085] The receiver 310 may be installed in a location where it can receive wireless signals bearing the relevant information, such as an exterior surface of a building. In an embodiment, the receiver 310 may be contained in a separate housing that is coupled to other components of the retransmission device 300. The receiver 310 may be an outdoor receiver, that is, the receiver 310 may be located outside of the building.

[0086] The ADC 320 may convert the wireless signal received by the receiver 310 into digital signal. In an embodiment, an analog filter (not shown) may be coupled between the receiver 310 and the ADC 320. The analog filter may filter out noise from the wireless signal. In an embodiment, the analog filter is a low-pass or band-pass filter.

[0087] The system bus 330 may connect various components of the retransmission device 300 to each other. The system bus 330 may be connected to the ADC 320, the memory 332, the processor 334, the user interface 336, and the modulator circuit 340.

[0088] The memory 332 may include a non-transitory computer readable medium that stores instructions executed by the processor 334. The memory 332 may include random access memory (RAM) and/or read-only memory (ROM). In other embodiments, instructions may be stored on another form of non-transitory computer readable media, such as an ASIC integrated with processor 334. [0089] The processor 334 may receive a digital signal from the analog-to-digital converter 320 through the system bus 330, extract the relevant information from the digital signal using pre-programmed instructions stored in the memory 332, and cause the modulator circuit 340 to generate a modulated signal including the relevant information. The processor 334 may extract the relevant information using a digital filter to isolate components of the digital signal that correspond to the relevant information.

[0090] The processor 334 may be coupled to the modulator circuit 340, and may cause the modulator circuit 340 to retransmit the relevant information from the wireless signal received from receiver 310 by outputting a modulated signal. In an embodiment, processor 334 may cause the modulated signal to have a different format than the wireless signal.

[0091] The user interface 336 may convey status information about the retransmission device 300, and receive inputs from a user. The user interface 336 may be connected to a display that can convey the status information to the user.

[0092] The modulator circuit 340 may output the modulated signal to a redistribution system. The modulator circuit 340 may include digital and/or analog circuitry that produces the modulated signal based on control by the processor 334. In an embodiment, the modulated signal is an analog voltage signal in accordance with a PLC protocol. Example PLC protocols include Universal Powerline Bus, XI 0, and LonTalk.

[0093] In an embodiment, the redistribution system may include a WLAN transmitter. The modulated signal may be a digital signal, and the modulator circuit 340 may output the modulated signal to the WLAN transmitter, and the WLAN transmitter may wirelessly transmit the modulated signal throughout the interior of the building.

[0094] In an embodiment, the redistribution system may include a mains power line, and the modulator circuit 340 may be a PLC modem. The modulated signal may be an analog voltage signal. The modulator circuit 340 may transmit the modulated signal to one or more electronic devices coupled to the mains power line by combining the modulated signal with a power supply voltage carried by the mains power line. The modulator circuit 340 may retransmit the relevant information by superimposing the modulated signal with the power supply voltage in accordance with control by the processor 334.

[0095] When the modulated signal is a PLC signal, the modulated signal may have a relatively low voltage and a high frequency, as compared to the power supply voltage. Accordingly, power supply circuits of the electronic devices plugged into the mains power line may filter or otherwise ignore the retransmitted signal as noise. For example, the power supply voltage may have a voltage of 120 V and a frequency of 60 Hz, and the retransmitted signal may have a voltage of less than 30 mV and a frequency of at least 3 kHz.

[0096] In summary, the retransmission device 300 may receive a wireless signal containing the relevant information, extract the relevant information, generate the modulated signal including the relevant information, and output the modulated signal to the redistribution system. Accordingly, the retransmission device 300 may retransmit the relevant information to indoor devices that may be unable to receive the wireless signal directly.

[0097] FIG. 4 illustrates a demodulator 400, according to an embodiment. The demodulator 400 may be coupled between a redistribution system and an indoor device.

[0098] The signal demodulator 400 may include a filter circuit 410, an ADC 420, a system bus 430, a memory 432, a processor 434, and a user interface 436.

[0099] The filter circuit 410 may receive a superimposed voltage from the redistribution system, and may filter out extraneous components from the superimposed voltage. The superimposed voltage may include a modulated signal superimposed with a power supply voltage. In an embodiment, the filter circuit 410 may apply a band-pass filter to the received superimposed voltage in order to extract the modulated signal. For example, if the power supply voltage has a frequency of 60 Hz, the filter circuit 410 may apply a band-pass filter with a lower cutoff frequency of greater than 60 Hz.

[0100] The ADC 420 may convert an analog signal from the filter circuit 410 into a digital signal and transmit the digital signal to the processor 434.

[0101] The system bus 430 may connect various components of the demodulator 400 to each other, including the ADC 420, the memory 432, the processor 434, the user interface 436, and the indoor electronic device. The memory 432 may be coupled to the processor 434, and may store instructions implemented by the processor 434. The processor 434 may extract relevant information from the digital signal transmitted by the ADC 420, and may output the relevant information to an electronic device.

[0102] The demodulator 400 could be integrated into the electronic device, or could be a separate module. [0103] Embodiments of several example systems are shown in the FIGS. 5, 6, and 7. These systems are provided as specific embodiments to promote a better understanding of the scope of this disclosure, and are not limiting.

[0104] FIG. 5 illustrates a system 500 receiving a GPS signal and distributing information from the GPS signal through indoor electrical wiring, according to an embodiment. The system 500 includes a GPS receiver 520, a modulator 530, demodulators 550a and 550b, and first and second indoor devices 560a and 560b.

[0105] The GPS receiver 520 may receive the GPS signal from the GPS satellite 510. The GPS signal may be embedded with relevant information such as timing information and location information from which the GPS receiver 520 can derive latitude, longitude, and elevation values. The GPS receiver is mounted on an external surface of the building in order to avoid signal attenuation and/or interference by the building.

[0106] The GPS receiver 520 may be plugged into an outdoor outlet 544. The GPS receiver may be plugged into the outdoor outlet 544 through the modulator 530 and, optionally, a data pre-processing device. In an embodiment, the GPS receiver 520 may be powered by voltage propagated throughout the electrical wiring 540 of the building.

[0107] The data pre-processing device may extract a signal including the relevant information from a signal including other components of the GPS signal, and may output the extracted signal to the modulator 530. The data pre-processing device may be coupled between the GPS receiver 520 and the modulator 530. In an embodiment, the data preprocessing device may filter out extraneous information corresponding to components of the GPS signal that may not be of interest to the first and second indoor devices 560a and 560b, such as GPS almanac data.

[0108] The modulator 530 packages the relevant information by generating modulated signal, which may be a high-frequency, low voltage signal embedded with the relevant information. The modulator 530 may superimpose the modulated signal with a power supply voltage over a hot wire and neutral wire of the electrical wiring 540.

[0109] The modulated signal sent over the electrical wiring 540 could be a synchronous signal with well-defined timing information, an asynchronous signal containing packetized timing and location information, or a combination of both. [0110] The electrical wiring 540 may carry a voltage differential between hot wire and a neutral wire. In an embodiment, the electrical wiring 540 includes a ground wire. The voltage differential may include the modulated signal superimposed with the power supply voltage. The electrical wiring 540 may be coupled to the outdoor outlet 544 and first and second indoor outlets 546a and 546b. The electrical wiring 540 may include a mains power line, phone line, or other electrical wiring located in the building.

[0111] Each power line demodulator 550a and 550b is coupled to a respective indoor electronic device 560a and 560b. Each power line demodulator 550a and 550b receives the superimposed voltage from the electrical wiring 540, extracts the relevant information from the modulated signal in the superimposed voltage, and delivers the relevant information to the respective indoor electronic devices 560a and 560b.

[0112] In an embodiment, the power line demodulators 580a and 580b may be modular devices that may be coupled between the electrical wiring 540 and the indoor electronic devices 560a and 560b. In an embodiment, the power line demodulators 580a and 580b may be plugged into the indoor outlets 544 and 540b directly, and the indoor electronic devices 560a and 560b may be plugged into the power line demodulators 580a and 580b. Alternatively, the power line demodulators 580a and 580b may be integrated into the indoor electronic devices 560a and 560b.

[0113] In the embodiment illustrated in FIG. 5, the first electronic device 560a is an indoor wireless femtocell, and the second electronic device 560b is a consumer electronics device. Each of the first and second electronic devices 560a and 560b may derive timing and/or location information from the externally mounted GPS receiver 530 via the building's electrical wiring 540.

[0114] The first electronic device 560a, which is a wireless femtocell, may use the timing and/or location information to maintain tight timing synchronization with external cell sites outside of the building. Accordingly, the first electronic device 560a may facilitate mobility handover and may minimize system interference resulting from transmissions that are not synchronized with external base stations.

[0115] Accordingly, relevant information, such as timing, frequency, and/or location information, is retransmitted to devices inside of the building through preexisting wiring within the building. [0116] FIG. 6 illustrates a system receiving GPS signal and distributing information from the GPS signal through an indoor wireless network, according to an embodiment.

[0117] FIG. 6 illustrates a possible implementation of this disclosure. A system 600 receives GPS signal and distributes information from the GPS signal through an indoor WLAN, according to an embodiment. The WLAN may be a Wi-Fi network.

[0118] The system 600 includes a GPS receiver 620, a signal modulator 630, first and second WLAN receivers 650a and 650b, and first and second indoor electronic devices 660a and 660b. In an embodiment, the system 600 further includes a WLAN transmitter 640. In another embodiment, the system 600 may be connected to the WLAN transmitter 640.

[0119] System 600 uses an existing indoor WLAN network to redistribute relevant information received by externally mounted GPS receiver 620 to the indoor electronic devices 660a and 660b. The relevant information may include synchronization information, such as timing, frequency and/or location information.

[0120] The signal modulator 630 may extract the relevant information from GPS signal received by the GPS receiver 620 from the GPS satellite 610, generate a modulated signal including the relevant information, and output the modulated signal to the WLAN transmitter 640. The WLAN transmitter 640 may wirelessly transmit the relevant information to the first and second indoor electronic devices 660a and 660b over a WLAN link. In an embodiment, the WLAN transmitter 640 is integrated into the signal modulator 630.

[0121] The modulated signal may include specially formatted Ethernet packets. In an embodiment, the packets contain highly accurate timestamp and location information, derived from the GPS signal.

[0122] Each of the WLAN receivers 650a and 650b may receive the packets sent over the WLAN link, and may derive a highly accurate local timing signal, and a highly accurate frequency reference from the packets. The local timing signal may be derived from timestamps contained in the received packets and/or arrival times at which the packets arrive at the WLAN receiver 650a or 650b.

[0123] The frequency reference may be derived from an interpacket arrival time and/or an average of packet timestamps over multiple received packets. For example, the frequency reference may be derived using a phase-locked loop (PLL) with a voltage controlled oscillator (VCXO) to maintain frequency accuracy between packet arrivals, or a frequency - locked loop (FLL) incorporating a fixed-frequency oscillator in conjunction with direct digital synthesis (DDS) techniques. The WLAN receivers 650a and 650b may derive the timing signal and/or the frequency reference using digital circuitry, analog circuitry, or both.

[0124] In an embodiment, the relevant information can be delivered wirelessly to the electronic devices 660a and 660b using the Wi-Fi standard. In addition to Wi-Fi, other local wireless transmission schemes including proprietary schemes utilizing licensed or unlicensed spectral bands could be used. For example, the WLAN transmitter 640 and the WLAN receivers 650a and 650b could correspond to a proprietary local retransmission system utilizing unique spread spectrum codes and operating in appropriate unlicensed spectrum (e.g., Federal Communications Commission (FCC)-defined industrial, scientific, and medical (ISM) bands), in order to locally redistribute timing, frequency and or location information with reduced risk of interference from nearby Wi-Fi devices with an appropriately designed transmission scheme.

[0125] FIG. 7 illustrates a system 700 receiving regional network signals via a proprietary wireless network and distributing information from the network signal through indoor electrical wiring, according to an embodiment. FIG. 7 illustrates a remote transmitter 710, a regional network receiver 720, a signal modulator 730, electrical wiring 740, first and second power line demodulators 750a and 750b, and first and second of indoor electronic devices 760a and 760b.

[0126] The signal modulator 730, the electrical wiring 740, the first and second power line demodulators 750a and 750b, and the first and second indoor electronic devices 760a and 760b may be respectively similar to the modulator 530, the electrical wiring 540, the first and second power line demodulators 550a and 550b, and the first and second indoor electronic devices 560a and 560b described above with reference to FIG. 5.

[0127] The system 700 may include the signal modulator 730, the first and second power line demodulators 750a and 750b, and the first and second indoor electronic devices 760a and 760b. The system 700 may receive relevant information, such as timing, frequency and/or location information, from a source other than a GPS source, and deliver the relevant information to the first and second indoor electronic device 760a and 760b.

[0128] The remote transmitter 710 may transmit a wireless signal including relevant information to the regional network receiver 720. The remote transmitter 710 may be local cellular site that broadcasts the wireless signal to specifically facilitate synchronization of regional devices. Alternatively, the remote transmitter 710 may transmit a timing signal sourced from the National Institute of Standards and Technology (NIST). In an embodiment, the wireless signal transmitted by the remote transmitter 710 includes timing and/or frequency information.

[0129] The regional network receiver 720 may receive the wireless signal from the remote transmitter 710. The regional network receiver 720 may be mounted outside of a building. The power line modulator 730 may be coupled between the regional network receiver 720 and the electrical wiring 740. The power line modulator 730 may extract the relevant information from the wireless signal received by the regional network receiver 720, and may propagate a modulated signal including the relevant information through the electrical wiring 740. In an alternative embodiment, the system 700 could transmit the relevant information via an indoor Wi-Fi network, similar to system 600 of FIG. 6.

[0130] FIG. 8 illustrates a process 800 for modulating a wireless signal and outputting relevant information from the wireless signal to a redistribution system, according to an embodiment. The process 800 may be carried out by a retransmission device.

[0131] At S810, a wireless signal is received from a remote transmitter. In an embodiment, the remote transmitter is a GPS satellite, and the wireless signal is a GPS signal. In another embodiment, the remote transmitter is part of a proprietary wireless network, and the wireless signal may be a regional timing signal. The wireless signal may be received by an outdoor receiver, which may be mounted on an external surface of a building.

[0132] The wireless signal includes relevant information that can be utilized by indoor electronic devices. The relevant information may include synchronization information, such as any of timing, frequency, and location information. In an embodiment, the relevant information includes any of a timing reference indicating a current time, a frequency reference, and location information from which a latitude, longitude, and altitude of the outdoor transmitter can be derived.

[0133] At S820, the wireless signal may be pre-processed. An analog filter such as a bandpass filter may be used to filter extraneous components of the wireless signal. In an embodiment, S820 is omitted from the process 800.

[0134] The wireless signal is converted from an analog signal to a digital signal at S830. In an embodiment, S 830 is performed by an ADC installed in the retransmission device. [0135] At S840, the relevant information is extracted from the digital signal converted by the ADC. In an embodiment, the relevant information is extracted by a processor.

[0136] At S850, a modulated signal is generated. In an embodiment, the modulated signal is generated by a modulator circuit controlled by the processor according to the relevant information extracted by the processor. The modulated signal may be embedded with the relevant information.

[0137] At S860, the modulated signal is output to a redistribution system. The modulator circuit may, for example, superimpose the modulated signal with a power supply voltage carried by the redistribution system. The relevant information from the wireless signal may therefore be retransmitted through the redistribution system via the modulated signal. The modulator circuit, for example, may perform S860 according to control by the processor.

[0138] In an embodiment, the modulated signal is an analog voltage signal, the redistribution system is a mains power line of a building, and the modulator circuit is a PLC modem. The PLC modem may retransmit the relevant information by superimposing the modulated signal with a power supply voltage along the mains power line. The mains power line may carry the superimposed voltage including the power supply voltage and the modulated signal. The power supply voltage may power one or more devices coupled to the mains power line. An indoor electronic device may receive the modulated signal over the mains power line, and may utilize the relevant information.

[0139] In an embodiment, the redistribution system includes an indoor wireless transmitter, e.g., a WLAN transmitter. The modulated signal may be output to the wireless transmitter by the modulator circuit, and may be distributed throughout an indoor space by the wireless transmitter over a wireless link. In this embodiment, the indoor electronic device may receive the retransmitted signal via a wireless receiver, e.g., a WLAN receiver.

[0140] FIG. 9 illustrates a process 900 for receiving a signal from a redistribution system, according to an embodiment. The process 900 may be performed by a demodulator. In an embodiment, the redistribution system is a mains power line, and the process 900 is performed by a PLC modem coupled to an electronic device.

[0141] A superimposed voltage may be received from the redistribution system at S910. In an embodiment, the superimposed voltage may be received from the mains power line through an indoor outlet. The electronic device may be powered through the indoor outlet. [0142] In an embodiment, the superimposed voltage may be pre-processed. For example, noise may be filtered from the superimposed voltage using an analog filter.

[0143] At S920, a modulated signal bearing the relevant information is extracted from the superimposed voltage. The modulated signal may be extracted using an analog filter. In an embodiment, the filter is a bandpass filter that filters out a power supply voltage in the superimposed voltage. For example, if the power supply has a frequency of approximately 60 Hz, a lower cutoff frequency of the filter may be greater than 60 Hz.

[0144] At S930, relevant information is extracted from the modulated signal. The relevant information may include timing, frequency, and/or location information. In an embodiment, the relevant information includes synchronization information, such as any of a timing reference, a frequency reference, and location information from which a latitude, longitude, and altitude of an outdoor receiver may be derived.

[0145] Embodiments of the present disclosure relate to a retransmission device, system, and method. A wireless signal is received by an outdoor receiver, and relevant components of the wireless signal are modulated onto a redistribution system in a building. The relevant components of the wireless signal are demodulated from the redistribution system, and transmitted to indoor electronic devices.

[0146] The retransmission device, system, and method provide a number of advantages over existing technology.

[0147] First, indoor devices may acquire relevant information from outdoor wireless signals, even when the indoor devices are not able to receive the outdoor wireless signals directly.

[0148] Second, unlike devices, systems, and methods that utilize indoor GPS technology, embodiments of the present disclosure can distribute relevant information from outdoor wireless signals to indoor devices using existing indoor redistribution systems, like mains power lines and WLAN networks.

[0149] Third, unlike devices, systems, and methods that utilize direct Internet links, embodiments of the present application can distribute relevant information quickly and accurately. Accordingly, devices that require highly accurate timing and/or frequency references (e.g., indoor femtocells) can rely on timing and/or frequency references distributed in accordance with the present disclosure.