TECHNICAL FIELD
[0001] The present disclosure relates generally to wireless communication. and in particular to synchronizing clocks in a wireless data network. More particularly, the present disclosure relates to time synchronization of radio stations in a wireless network.
BACKGROUND
[0002] There are different wireless network time synchronization methods to execute network operations. So far available methods use global navigational satellite system (GNSS) or without GNSS support and also difference in network topologies like distributed, mobile ad-hoc, point to point etc. In the patent publication US7876790, “Apparatus and method for performing time synchronization using GPS information in communication system” Discloses an apparatus and a method for performing time synchronization by using Global Positioning System (GPS) information in a communication system. The apparatus comprises a grand-master node having a GPS receiver, for generating a synchronizing message required to synchronize time on slave nodes by using Time Of Day (TOD) information received from the GPS receiver and at least one slave node for receiving the synchronizing message required to synchronize time from the grand-master node or from another slave node, for carrying out time synchronization operation by using an Offset and Frequency Compensation Clock (OFCC) synchronization process supporting time offset and frequency separation compensation, and for generating a synchronizing message required to synchronize time on other slave nodes.
[0003] “Continuous Clock Synchronization in Wireless Real-Time Applications” with DOI 10.1109/RELDI.2000.885400 is published in Proceedings 19th IEEE Symposium on Reliable Distributed Systems SRDS-2000, and says that Continuous clock synchronization avoids unpredictable instantaneous corrections

of clock values. This is usually achieved by spreading the clock correction over the synchronization interval. In the context of wireless real time applications, a protocol achieving continuous clock synchronization must tolerate message losses and should have a low overhead in terms of the number of messages. The paper presents a clock synchronization protocol for continuous clock synchronization in wireless real time applications. It extends the IEEE 802.11 standard for wireless local area networks. It provides continuous clock synchronization, improves the precision by exploiting the tightness of the communication medium, and tolerates message losses. Continuous clock synchronization is achieved with an advanced algorithm adjusting the clock rates. It presents the design of the protocol, its mathematical analysis, and measurements of a driver level implementation of the protocol on Windows NT.
[0004] In the patent publication US20090086764, “System and method for time synchronization on network” reveals a system and method for time synchronization on a network is provided. According to the system and method for time synchronization, a slave clock device does not continuously receive a time synchronization message periodically transferred from a master clock device and thus does not correct its time upon all such occasions. Rather, the slave clock device requests time information from the master clock device only when the slave clock device needs to correct its time, and receives a time synchronization message transferred from the master clock device and compensates for its time deviation only while the slave clock device is activated, thereby reducing its power consumption and amount of computation.
[0005] Above presented already existed stuff on the time synchronization methods. In the patent as said in US7876790, as brief to say that the system is using GPS information for time synchronization but the present invention is not at all using GPS system and is using 1PPS rubidium clock signal at master or central radio station as the network reference through which the central radio station generates the timing information using TDMA/TDD slots architecture. In the

IEEE publication with DOI 10.1109/RELDI.2000.885400 superficially says that it does continuous time synchronization in which the master sends continuously sync messages to the slave and expects slave timing information in the reverse link to compensate the timing offset. But in the present invention the master (central) radio station does not expect any timing information from the remote (slave) radio station because the central radio station only expects the uplink control frame through which the central radio station calculates the round trip delay and hence computes the one way propagation delay as the channel is symmetric in both direction meaning downlink and uplink.
[0006] In the patent as said in US20090086764, the slave requests the timing information from the master station when it requires and corrects its timing information for synchronization. But in the present invention, the central (master) radio station continuous meaning in each downlink control frame sends the timing information and at the remote (slave) radio station, moving average of the one way propagation delay is computed and gets the stable centriod for the one way propagation delay to compensate the jitter in the estimation of the propagation delay and is useful in the time synchronization equaton-3 as covered in the following summary of the present invention.
SUMMARY
[0007] An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.
[0008] The present invention of 1 PPS time synchronization is designed and developed for point to multi point (PTMP) wireless radio links and is implemented on the radio platform for real time operations. The present invention does not require Global Navigation Satellite System (GNSS) for synchronizing the PTMP radio network. The radio stations in the radio network is divided into either master radio

station (central) or slave radio station (remote) in accordance with functionalities and deployment scenario. The PTMP network comprises one master radio station with hot redundancy and a maximum of “N” slave radio stations separated at a maximum aerial distance of “S” kms from the master radio station. The number of slaves “N” depends on the network parameters and/or requirements of the network.
[0009] In the PTMP network only the master radio station can communicate with the slave radio stations and there is no communication between the slave radio stations. The main clock source for the PTMP network synchronization is rubidium (atomic) clock and is provided only to the master radio station. The master radio station derives the virtual local timer using one pulse per second (1 PPS) signal from the rubidium clock source to run time division multiple access / time division duplex (TDMA/TDD) time slots. By using TDMA/TDD channel access mechanism, an uplink and downlink control frame transmissions occur over the air between the master radio station and the slave radio stations. Therefore all the slave radio stations synchronize with the master radio station independently and hence synchronization of the entire PTMP wireless radio network is obtained without using a satellite system. The PTMP network is capable of self synchronization in real time critical radio network. The object of this invention is to obtain 1 PPS time synchronization between the main radio station and slave radio stations and accuracy with which the slave radio station generates 1 PPS signal with respect to the main radio station. Therefore synchronization of the entire PTMP wireless radio network is obtained without satellite system signal information. A centralized TDMA/TDD mechanism is used for synchronizing the PTMP network, such that the master radio station is a network master for the entire PTMP network for controlling the activities. The present one pulse per second (1 PPS) time synchronization method is not dependant on the GNSS system and is self synchronization capable PTMP real time critical radio network.
[0010] Other aspects, advantages, and salient features of the invention will become

apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention
BRIEF DESCRIPTION OF DRAWINGS
[0011] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
[0012] FIG. 1 illustrates a block diagram of point to multi point (PTMP) network topology.
[0013] FIG. 2 illustrates the system configuration of the PTMP network.
[0014] FIG. 3A illustrates time division multiple access (TDMA) / time division duplex (TDD) uplink/downlink frame architecture.
[0015] FIG. 3B illustrates a control slot offset duration for a slave radio station for a single super frame.
[0016] FIG. 3C illustrates super frame count for TDMA/TDD slot architecture.
[0017] FIG. 3D illustrates downlink control frame.
[0018] FIG. 3E illustrates round trip transmission of frames between master radio station and slave radio station.
[0019] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For

example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION OF DRAWINGS
[0020] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0021] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0022] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.

[0023] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic is intended to provide.
[0024] FIGS. 1 through 3E, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that would limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged communications system. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions, in no way limit the scope of the invention. Terms first, second, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. A set is defined as a non-empty set including at least one element.
[0025] Those skilled in this technology can make various alterations and modifications without departing from the scope and spirit of the invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.
[0026] FIGS. 1-3E are merely representational and are not drawn to scale. Certain portions thereof may be exaggerated, while others may be minimized. FIGS. 1-3E illustrate various embodiments of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
[0027] In the foregoing detailed description of embodiments of the invention, various features are grouped together in a single embodiment for the purpose of

streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description of embodiments of the invention, with each claim standing on its own as a separate embodiment.
[0028] FIG. 1 illustrates network topology of the point to multi-point (PTMP) network. One master radio station 101 with a stand-by and “N” slave radio stations 102 are deployed in the star topology fashion. The maximum distance between the master radio station 101 to slave radio stations 102 is “S” Kms. The slave radio stations 102 can be at any location in the topology according to the application scenario. The uplink and downlink direction are illustrated and represents the communication between master radio station 101 and slave radio stations 102. The slave radio stations 102 do not communicate between each other.
[0029] The present invention of 1PPS time synchronization is applicable for point to multi point (PTMP) wireless radio network for ground based, line of sight (LOS) static (no mobility during operational time) network deployment and contains one master radio station 101 with hot redundancy and “N” slave radio stations 102. The number of slave radio stations 102 “N” depend on the network parameters and/or requirements of the network. When primary master radio station 101 health goes bad, the redundant (hot standby) master radio station begins the real time operations. The slave radio stations 102 are deployed at a maximum aerial distance of “S” Kms to carry out the real time operations as commanded at the master radio station.
[0030] The radio stations in the radio network is divided into either master radio station 101 (central) or slave radio station 102 (remote) in accordance with functionalities and deployment scenario. The PTMP network comprises one master

radio station with hot redundancy and a maximum of “N” slave radio stations separated at a maximum aerial distance of “S” kms from the master radio station. The number of slaves “N” depends on the network parameters and/or requirements of the network. As this is a PTMP network, only the master radio station 101 can communicate with the slave radio stations 102 and there is no communication among the slave radio stations 102. The main clock source for the PTMP network synchronization is rubidium (atomic) clock and is provided only to the master radio station. The master radio station derives the virtual local timer using one pulse per second (1 PPS) signal from the rubidium clock source to run \time division multiple access / time division duplex (TDMA/TDD) time slots. By using TDMA/TDD channel access mechanism, an uplink and downlink control frame transmissions occur over the air between the master radio station and the slave radio stations. Therefore all the slave radio stations synchronize with the master radio station independently and hence synchronization of the entire PTMP wireless radio network is obtained without using a satellite system.
[0031] FIG. 2 depicts the master radio station 101 with hot stand-by and two slave stations 102. The master radio station 101 comprises a beam switching antenna 103, a beam switch unit 104 that is connected to the beam switching antenna 103 through radio frequency (RF) cables. The beam switch unit 104 is connected to the outdoor unit 105 by control cable and RF cable. The outdoor unit 105 is connected to switch control unit 106 through control cable and RF cable. The switch control unit 106 is connected to indoor unit (IDU) normal 107 and IDU standby 108 by control cables and RF cables. The slave stations 102 comprise a directional antenna at slave station with antenna alignment 109, outdoor unit 110, indoor unit 112 and antenna alignment units 112 in PTMP network.
[0032] The master radio station 101 comprises beam switching antenna 103 for covering the slave radio stations 102 in any of the beam pattern for real time communications. The slave radio stations 102 comprise a directional antenna with rotational unit/ antenna alignment 109 to align the antenna direction with the central

or the main radio station 101. The master radio station 101 comprises hot redundancy, indoor unit 107, outdoor unit 105, beam switch antenna 103 and directional antenna and antenna alignment unit 109, etc. The master radio station 101 comprises beam switching antenna 103 for covering 360 ° as each beam radio pattern width is aimed for “B”.
[0033] FIGS 3A-3D illustrate time division multiple access (TDMA) / time division duplex (TDD) uplink/downlink slots and framing information. FIG. 3E illustrates round trip transmission of frames between master radio station 101 and slave radio station 102. The TDMA slot comprises one downlink and one uplink sub slots. One TDMA/TDD frame comprises control and communication slots. A super frame comprises TDMA/TDD frames and auxiliary slots. One super frame covers control slots for all the slave radio stations. A hyper frame comprises multiple super frames and duration of one hyper frame is one second. For synchronizing the slave radio stations 102 with the master radio station 101 control slots are utilized. FIG. 3B illustrates a control slot offset duration for a slave for one super frame for calculating start of the downlink control frame offset time duration from the beginning of each super frame. FIG. 3C illustrates the super frame count for TDMA/TDD slot architecture and explains briefly about the calculation of the super frame count out of „Y‟ super frames in the TDMA/TDD hyper frame. FIG. 3D illustrates a link layer down link frame control frame and explains briefly about the down link control frame fields. The down link control frame contains typical parameters like propagation delay time, frame processing time; control slot offset duration and super frame count.
[0034] A time division multiple access (TDMA) medium access control (MAC) protocol is used for allotting the slots among network radio stations. The total TDMA/TDD slots are fixed (static) for the slave radio stations 102 and assigned and controlled by the master radio station 101. Each TDMA slot is sub divided into downlink/ uplink using time division duplex (TDD) technique at a physical layer. A TDMA/TDD uplink is accessible by the slave terminals 102 for transmitting the

control frames to the master radio station 101 and downlink is accessible to the master radio station 101 for transmitting the control frames to the corresponding slave radio station 102. Each uplink transmission is followed by a corresponding down link transmission for the corresponding slave radio station 102. The TDMA/TDD control frames carry the timing information to synchronize the network radio station. The TDMA/TDD slot architecture is designed in a way to support the time synchronization for the PTMP network.
[0035] Each downlink/uplink comprises ramp up time duration, actual control data time duration, propagation and guard time duration. One downlink along with one uplink time duration is one TDMA slot duration. The TDMA/TDD architecture comprises hyper frames, super frames and TDMA/TDD frames for the network control and data communications. The TDMA/TDD frame comprises “C” control and “D” data slots and the slots comprise downlink and uplink. The super frame comprises “Z” number of TDMA/TDD frame slots and “R” auxiliary slots. The hyper frame comprises “Y” super frames with a duration of one second (1 pulse per second (PPS)). The TDMA/TDD slots are depicted in the fig-3 with entire picture of the TDMA/TDD frames, super frames and hyper frame.
[0036] An executable device processor is a platform for implementing TDMA/TDD for time synchronization. The executable device processor has a core speed of “G” MHz. The core of the executable device processor runs with “M” parts per million (“M” PPM) stable external temperature compensated crystal (TCXO) oscillators. The TDMA/TDD method is implemented at a layer-2 of indigenous protocol stack on the executable device processor chip to minimize timing jitter that is achieved on order of few microseconds such as 1 or 2 microseconds at each slave radio station 102. The TDMA/TDD frame comprises control and data frames. The TDMA/TDD super frame duration is “X” msec. The “Y” super frames make one hyper frame of duration one second. The TDMA/TDD frame duration is “W” milli seconds such that each slave radio station 102 is provided an access to the channel with the master radio station 101. The control

frame data integrity is evaluated with check sum and jamming and channel conditions are evaluated with received signal strength indication (RSSI) and bit error rate (BER) as shown in FIG. 3D.
[0037] The timings of the master radio station 101 and slave radio stations 102 should be at a same pace and should be accurate for executing real time critical operations with estimated latencies from the master radio station 101 to the slave radio stations 102. For the implementation of the 1 PPS time synchronization at layer-2 on executable device processor chip, the master radio station 101 is interfaced with the rubidium clock source. The rubidium clock source provides signals to the master radio station 101 and the master radio station 101 receives 1 PPS signal from the rubidium clock source. The master radio station 101 with 1 PPS generates the timing information or time stamps. The master radio station‟s executable device processor gets interrupts for every one second from the rubidium source to continuously run TDMA/TDD slots with stability. The slave radio stations 102 have to generate the 1 PPS signal with the same pace of the 1 PPS signal provided at the master radio station with an accuracy of “α” micro seconds offset as the master radio station 101 and the slave radio stations 102 are a part of a self synchronization PTMP radio network. The slave radio stations 102 generate the 1 PPS signal by getting timing information from the master radio station over the air using TDMA/TDD parameters.
[0038] The executable device processor of the master radio station 101 samples the 1 PPS from the rubidium clock source and derives the slots for the Time Division Multiple Access (TDMA) / Time Division Duplex (TDD) by using its local (virtual) timer. The executable device processor runs local timer called as the slot timer with period equal to the downlink plus uplink time durations (TDMA). The master radio station 101 transmits downlink control frames with timing information to the each slave radio station 102 over the air. The timing information comprises: a one way propagation delay time (Di) along with processing delay (PD1), downlink control slot time duration offset from the start of super frame for the corresponding slave

radio station (TCSO), and super frame count (Yn), where “Di” is one way Propagation Delay Calculated at master Radio Station for each slave and „i‟ represent Slave radio Station Identification Number (1, 2, .up to N), “PD1” is processing delay (includes frame processing, code execution delays and etc), “TCSO” is control slot offset duration from beginning of the super frame at the master radio station 101 “Yn” is number („n‟ th super frame out of „Y‟ super frames in one second duration). The downlink control frame comprises typical timing parameters such as propagation delay time, frame processing time; control slot offset duration, and super frame count.
[0039] The downlink control slot time duration offset and super frame count are computed by the master radio station 101 from the Time division multiple access (TDMA) / time division duplex (TDD) slots running at the time of downlink control frame transmission as shown in FIGS. 3E. The one way propagation delay time (Di) parameter is calculated from the round trip time and the master radio station 101 computes round trip time. The master radio station 101 shall note down slot local timer value (C1) before transmitting downlink control frame to the corresponding slave radio station 102 and also shall note down slot local timer value (C2) after receiving the uplink control frame from the corresponding slave radio station 102 as shown in FIG. 3E. The master radio station calculates duration of the round trip time TRTT for each slave radio station 102.
TRTT = (C2 - C1) * local timer counter sampling time at master radio
station
[0040] The round trip time comprises downlink plus uplink control frames active transmission duration, frame processing delays for downlink plus uplink code execution delays and propagation delays in both downlink and uplink directions. As the channel is symmetrical, propagation delays in both directions are same. The one way propagation delay time (Di) plus processing delay (PD1) parameters can be calculated as:

Di + PD1 = TRTT / 2 – TATD, where “TATD” is active slot transmission duration and “PD1” is processing delays estimated at master radio station.
[0041] The total uplink/downlink slot duration may be given as
TUODSD = TATD + TGT + Di , where TUODSD is uplink/down link slot duration, TGT is guard time, and Di is one way propagation delay of „i‟ the slave identification number. The timing information parameters are sent by the master radio station 101 to each slave radio station 102 over the air in the corresponding control downlink frame for the 1 PPS time synchronization. The 3 timing information parameters are sent by the master radio station 101 to the each slave radio station 102 over the air in the corresponding control downlink frame for the 1 PPS time synchronization.
[0042] The executable device processor of the slave radio station 102 receives the downlink control frames and validate the downlink control frames by the check sum of the frame. The downlink frame is de-serialized by the slave radio stations 102 and extracts the required fields for the time synchronization. A local (virtual) timer of the slave radio station 102 is configured for the 1 PPS derivations and is synchronized to the 1 PPS at the master radio station 101. The local timer of the slave radio station 102 is initialized with an offset time count that compensates active transmission duration, moving average one way propagation delay, control frame processing delay, control slot offset duration for the particular slave radio station 102, and super frame offset duration and processing delay of code execution. The master radio station calculates the round trip time (RTT) by registering TDMA/TDD slot timer count register value (C1) before just sending down link control frame to the corresponding slave radio station and by registering the present slot timer counter register value (C2) just after receiving the uplink control frame from the corresponding slave radio station, that is, RTT = C2- C1.
[0043] The below equation may be used for assigning the local timer counter register of the slave radio station 102 for synchronizing 1 PPS signal with the master radio station 101.

TRT LT TCNT = ( TATD + TMAPD + PD1 + TCSO + Yn *X+ PD ) / CST
where TRT LT TCNT is a local timer count register of a slave radio station 102, processing delays (PD) is estimated at slave radio station, TMAPD is moving average one way propagation delay, X is Super frame time duration, TCST is local timer sampling time. TMAPD = (Di1 + Di2 ………N1 times) / N1, where Diq is one way propagation delay, „i‟ is slave identification number and „q‟ is 1 to N1.
[0044] The moving average is calculated for the one way propagation delay to get a stable propagation delay from the last N1 one way propagation delay values. By using the slave local timer, 1 PPS is derived with an accuracy of “α” micro seconds with master station‟s 1 PPS signal and jitter with tens of nano seconds with slave radio station‟s local timer. Therefore the 1 PPS time synchronization is obtained to execute real time critical operations in the real time with estimated latencies from the master radio station 101 to the slave radio stations 102.
[0045] It is understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively.

1. A method for performing one pulse per second time synchronization for
point to multi point (PTMP) wireless radio network using TDMA/TDD, said method comprising:
interfacing a master radio station with a clock source;
receiving a one pulse per second signal from said clock source for generating a TDMA/TDD slots by said master radio station;
transmitting downlink control frames by said master radio station with timing information to a plurality of slave radio stations;
transmitting an uplink control frame by said slave radio station to said master radio station;
computing roundtrip time by said master radio station by determining slot local timer value before transmitting a further downlink control frame to a corresponding slave radio station and determining slot local timer value after receiving a uplink control frame from said corresponding slave radio station.
extracting one or more fields of said transmitted downlink control frames by said corresponding slave radio station;

validating integrity of said received downlink control frame by evaluating a checksum in said downlink control frame by said corresponding slave radio station; and
synchronizing said corresponding slave radio station to one pulse per second of said master radio station, upon validating, by configuring a local timer of said corresponding slave radio station based on said extracted fields of said transmitted downlink control frames by said corresponding slave station.
2. The method as claimed in claim 1, wherein said clock source is a rubidium clock source.
3. The method as claimed in claim 1, wherein said master radio station samples said received one pulse per second signal from said clock source for deriving TDMA/TDD slots.
4. The method as claimed in claim 1, further comprising estimating said round trip time through which said master radio station calculates one way propagation delay and said master radio station calculates said round trip time by registering slot timer count register value before sending said downlink control frame to said corresponding slave radio station and by registering a present slot timer counter register value after receiving said uplink control frame from said corresponding slave radio station.

5. The method as claimed in claim 1, wherein said time division multiple access slot architecture comprises TDMA/TDD frames, super frames and hyper frame for transmitting downlink or uplink control frames.
6. The method as claimed in claim 5, wherein said super frame comprises a plurality of TDMA/TDD frames such that said super frame provides an opportunity to each of said plurality of slave radio stations to transmit a corresponding control frame over air.
7. The method as claimed in claim 5, wherein said hyper frame comprises a plurality of super frames such that said hyper frame duration is one second.
8. The method as claimed in claim 1, wherein said timing information comprising a round trip time, super frame count from starting of a corresponding hyper frame, a control slot offset time duration from starting of said super frame for said corresponding slave radio station are timing information that are transmitted over within said point to multi point network for one pulse per second time synchronization.
9. The method as claimed in claim 1, wherein said slave radio station generates a one pulse per second signal with an accuracy of micro seconds and jitter with nano seconds with said slave radio station local timer by configuring local timer count register of said slave radio station.