SYNCHRONIZATION OF WIRELESS NETWORKS

TECHNICAL FIELD

The invention is related to a device which enables high precision time synchronization that can be used in wireless data recording networks.

PRIOR ART

Wireless sensor networks are one of the commonly used data recording systems. These systems are data recording units which operate with the logic of sensors in different physical positions receiving data and storing said data or transferring them to a center. As wearable systems are being commonly used nowadays, data recording systems having portable sensors on the human body have become prevalent. The fact that these units are wireless, has enabled these systems to be more flexible and to be used in a wide range of fields.

The information received from these systems is combined synchronously or by processing the records afterwards and a single data record is obtained. However this situation brings about a problem with it. This is the recording time information of the data received from the units.

This situation has necessitated the synchronization of the times of the units with each other. While the time synchronization between said units allow 1 minute precision in cases like transferring of information such as temperature, and ambient pressure which are slow changing information, the data obtained at high speeds become the source of significant errors.

The development of MEMS technologies can carry out sampling with high sampling rates (32 KHz) especially in issues, particularly such as the analysis of mobile systems. This situation shows that the synchronization of the times of units needs to be synchronized with precision.

Present synchronization systems use different methods in order to provide time synchronization between units. Some of these methods are used in wired systems and the precision such systems provide have been provided in the table below.

Time Table;

As it can be seen from the table, precision can be obtained at micro and nano second levels only with wired systems.

Different methods are used for synchronization in wireless systems. Synchronization is carried out with these methods (Pairwise, Centralized multi-hop, TPSN, FTSP, PTP) basically by establishing connection between two points with known network systems and following this by carrying out different synchronization methods over these connections. The performance with such systems is at ms levels.

The algorithms used in synchronization systems bring about loads on the processer and they prevent real time critical procedures from being carried out.

The loads created on processors due to synchronization algorithms and the modules that provide communication between units cause the designs to be more complicated and they lead to the increase of the sizes of the wearable units besides increasing their costs.

Synchronization systems need to reduce the sampling time to 31.25 microseconds that has been provided for a 32 KHz system that has been given as an example. Due to this reason, the matching of data received from different nodes becomes difficult and this leads to a significant source of error.

Latency and non synchronization could be caused as the units may receive the radio signals with lower efficiency due to their different positioning.

The size and the weight of the unit can be some of the significant sources of error due to the inertial effects especially in recording systems related with mobility. A couple of the obstacles which prevent the units from being small sized are the communication circuits and antenna which are formed to provide communication by units.

The communication between receiver networks used under water or in mediums with different densities is difficult. The radio systems used in such cases are quite bulky and relatively short range.

BRIEF DESCRIPTION OF THE INVENTION

The invention subject to the application is related to a device which enables time synchronization in wireless data recording networks.

The aim of the invention is to provide a device which enables high precision time synchronization that can be used in wireless data recording networks.

Another aim of the invention is to provide a device to be used for the synchronization of recording units that need to be wireless, portable and small sized even though they are to be used particularly in small areas.

The method used in this invention leads to an excess load on the recording system. The sensors to be placed on the recording unit by means of this invention can provide synchronization precision at ns levels as they are sensors having response times at ns (nanosecond) levels.

As the required physical space of this invention is small it enables the units to be as small sized as possible.

Said invention can be used for the synchronization of recording units that need to be wireless, portable and small sized even though they are to be used particularly in small areas. Particularly wearable units that are used in the health sector can be evaluated within this scope. It shall be enabled for the data in the records to belong exactly to the same time if inertial measurement units at high speeds used for example to carry out motion analysis, perform recording at 32000 record/sec per unit. These units can be recording units that can be used without affecting unit sizes and without leading to performance losses in sensor recording units that need to be used under water. The methods that can be used under water do not allow precise synchronization due to the effects of water on the radio signals. Synchronization provided with light does not lead to this problem.

A preferred embodiment of the invention can be used on applications carried out on a plurality of participants where the participants are not physically close to each other. Such synchronization systems can be used for example, in motion capturing systems used in the cinema and theatre sectors.

Recording mediums have conditions that prevent the usage of radio signals. The recording mediums on large machines can be included within this group. The wired synchronization of these units is not possible due to their mobile structures.

Other applications are usages such as the swarm attacks of unmanned aerial vehicles, drones in military fields. In such cases the wireless communication of unmanned aerial vehicles can be cut off using signal cutters. Due to this reason the synchronization of units and event triggers can be carried out with this method.

Another embodiment of the usage is again in wireless synchronization systems of underground pipe lines having a distributed structure and mine fields.

According to another embodiment the invention can be used for the synchronization of distributed seismographs and earth electrical analysis measurement systems.

Another preferred embodiment of the invention comprises a receiver with a response time between 2-6ns (nanoseconds).

Another preferred embodiment of the invention comprises a receiver positioned at different points by taking into consideration the usage area and location. The sensor part can be positioned on any desired section of the device. Thereby it is enabled for a synchronization signal to be received during usage. Another preferred embodiment of the invention comprises a light source unit which enables usage under water.

According to a preferred embodiment of the invention the response time established following the reception of light on the receiver is higher than 2-6ns.

Another preferred embodiment of the invention has a small sized structure (which can particularly be used in mobile and small sensor networks) which enables synchronization of recording units that need to be wireless, mobile and small sized.

Another preferred embodiment of the invention has a structure that enables the data in records to belong to the exact same time.

Another preferred embodiment of the invention has a structure that enables it to be used under water.

According to another preferred embodiment of the invention, the invention comprises a recording unit that can be used without affecting unit sizes and without leading to performance losses in sensor recording units that need to be used under water.

According to another preferred embodiment of the invention the light intensity used in the light source unit is 400-1000 watt-seconds.

According to another preferred embodiment of the invention the light having an intensity of 400-1000 watt-seconds used in the light source unit is on for l/lOO.OOOs.

FIGURES

The figures prepared in order to further describe the synchronization of Wireless Receiver Networks developed by means of this invention have been described below.

Figure 1. General view of the recording unit

Figure 2. External view of the recording unit

Figure 3. Synchronization of multiple units REFERENCE NUMBERS

The parts and elements in figures prepared in order to further describe the synchronization of Wireless Receiver Networks developed by means of this invention have each been numbered and the reference of each number has been disclosed below.

1 Light source unit

2 Receiver

3 Data recording units

DETAILED DESCRIPTION OF THE INVENTION

The novelty subject to the invention has been described with examples that do not have any limiting effect but have been provided to further describe the subject matter of the invention.

The synchronization of Wireless Receiver Networks developed by means of this invention is formed of data recording units (3) and a light source unit (1) which provides the synchronization of said units. The receiver (2) on the data recording unit (3) has a response time of 2-6ns. This receiver (2) forms an electrical response, 2-6 sec after receiving light thereon. In the design of the data recording unit (3), the data from the receiver (2) is used as an interrupt source, creating a mark on the recording without the use of additional processing power, allowing the units to synchronize according to this marker. Even though the light source to be used here can have different features, it is formed of flash units which can establish high intensity light at a short period of time in order to provide a homogenous record on the receiver. Thereby the reference time marking of units at different locations are enabled and synchronization of said units are provided accordingly.

An alternative usage is transferring to the sensors having a SYNC pin in order to synchronize the signal created by the receiver, thereby providing higher precision timing. In such a case the triggering process is carried out by the sensor not the microprocessor.

The receiver (2) on the unit can be positioned at different points by taking into consideration the usage area and the positioning of the unit or its reception angle can be increased by using a plurality of receivers (2). The usage of light for synchronization allows usage without problems or loss of performance in environments having different densities such as under water.

When the detailed description mentioned above is taken into consideration the invention is a Synchronization Device for Wireless Receiver Networks, characterized by comprising;

• at least one light source unit (1) which enables marking of reference time of units at different positions and the synchronization thereof accordingly, which can establish high intensity light comprising flash units in order to provide homogenous recording on the receiver.

• at least a data recording unit (3), comprising at least a sensor having response times at ns’ levels which allows synchronization of the units according to a marker by forming a mark on the record using the data received from the receiver as an interruption source,

• at least a receiver (2) which is positioned on the data recording unit (3) which enables to increase the reception angle if at least two receivers are present, which creates electrical responses at nanosecond levels when light is received thereon.

The light source unit (1) can allow the usage of light having different features according to ambient conditions. The intensity of the light can be adjusted according to the usage area. The intensity of light used in these products can be defined as watt-second. This value can be between 400-l000watt seconds. However by changing the discharge times of the capacitors that are being used, the usage time of the light at this intensity can be 1/1000 s (seconds).

Synchronization Method of the Synchronization Device of Wireless Receiver Networks, characterized by comprising;

• creating an electrical response 2-6ns after light is received on the receiver (2),

• Synchronization of the units by the data recording unit (3) using the data received from the receiver (2) as an interruption source, according to a marker where said mark is created on the record.

Another Synchronization Method of the Synchronization Device of Wireless Receiver Networks, characterized by comprising the following process steps;

• a signal is created by the receiver (2), • the signal created by the receiver (2) in order to use higher precision timing is transferred onto the sensors having a SYNC (synchronization) pin in order to provide synchronization,

• the triggering process is carried out by the sensor,

• synchronization is performed.