System and method for wireless exchange of data in a non-real-time data communications system

• US 6,567,397 B1
• Filed: 02/15/2000
• Issued: 05/20/2003
• Est. Priority Date: 02/15/2000
• Status: Expired due to Fees

• Current Assignee: Bizcom USA, Inc.
• Original Assignee: Sophia Communications, Inc. (Bizcom USA, Inc.)
• Inventors: Fries, Robert, Smigelski, Thomas, Smith, Gordon, Iacopetti, Paul, Jewer, Al, Pienkowski, Edward C., Ponschke, Michael P. Sr., Campana, Thomas J. Jr., Scott, Gib
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): LEE, CHI HO A
• Application Number:
  US09/500,963
• Time in Patent Office: 1,190 Days
• Field of Search: 370/321, 370/332, 370/337, 370/347, 370/349, 370/465, 370/468, 370/471, 370/475, 370/474, 370/389, 370/392, 370/477, 455/561, 455/560, 455/393, 714/777, 714/784, 714/748
• US Class Current: 370/349
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters

Abstract

A method of non-real-time two-way wireless data communications using a synchronous time division multiplexed architecture (TDMA) protocol in a communications system having a plurality of fixed base stations (BS) and a plurality of receiver/transmitters (RTs), wherein a BS controller dynamically changes a plurality of data blocks in both an uplink and a downlink data frame, a plurality of data rates, a plurality of signal modulation techniques, and a plurality of frequencies according to a computer analysis of received signals in order to provide optimization of the system. The method further includes overhead data reduction techniques using abbreviations for identification character strings and concatenations of downlink data messages. Embodiment of a novel emergency alarm resolution techniques and a plurality of message collision avoidance techniques improves response times for remote transmissions.

Claims

1. In a two-way wireless communications system comprising a plurality of base stations (BS) under control of a computer and a plurality of receiver/transmitters (RTs), wherein each of said BS includes a radio resource manager (RRM) controlling a single frequency, and each of said RTs has a unique identification address (ID), a method for transferring data from said BS to one or more of said plurality of RTs, comprising the steps of:

creating a plurality of serial data bit stream (SDBS) signals in said computer, each of said SDBS signals comprising an unencoded preamble data packet identifying a unique group address of one or more of said RTs;

a 4 bit Hamming Code for correcting a single byte in the preamble; and

an encoded frame data packet which includes an RT notification data block;

transferring each one of said plurality of SDBS signals to one of said RRMs;

transmitting said plurality of SDBS signals;

receiving said SDBS signals in each of said RTs; and

,

decoding said encoded frame data packet of a signal only in RTs identified in the notification data block.

2. The method according to claim 1, wherein said encoded frame data packet is encoded using a Reed-Solomon (RS) 56/64 encoding algorithm.

3. The method according to claim 1, wherein said unencoded preamble data packet comprises:

a frequency tone which is used for automatic gain control (AGC) and frequency calibration in the RT;

a first data word which describes an offset to a precise starting location of said frame data packet; and

a second unique data word indicating the most complex one of a plurality of modulation techniques that characterize said frame data packet in said SDBS signal.

4. The method according to claim 1, wherein said encoded frame data packet comprises:

a transceiver equalization data block;

a header block;

a transceiver notification data block comprising a plurality of IDs each one corresponding to a destination RT;

an acknowledgment (ACK) block;

a message data block; and

a reserved redundant group data block.

5. The method according to claim 4, wherein said transceiver equalization data block comprises a finite time period wherein are transmitted one or more signals designed to stimulate a characterization response in each one from the plurality of RTs.

6. The method according to claim 5, wherein at least one of said one or more signals is a pulse.

7. The method according to claim 4, wherein said header block comprises:

an identification name of said base station;

a listing of a plurality of transmission frequencies available at said base station;

a listing of a plurality of transmission frequencies available at a plurality of alternative base stations which are adjacent to said base station;

a calendar date; and

a time.

8. The method according to claim 7, wherein any data intended for inclusion in said header block that exceeds a predetermined bit length of said header block will be included in the header block of subsequent SDBS signals.

9. The method according to claim 4, wherein said plurality of IDs in the notification data block comprises a sequence of one or more of a plurality of equipment identification numbers (EINs), each EIN corresponding to a unique one of said plurality of RTs and each EIN being encoded using an abbreviation means.

10. The method according to claim 9, wherein said abbreviation means comprises a substitution of a predetermined number of sequential characters in an EIN by a four bit fixed (4BF) code word from a plurality of 4BF code words, each code word corresponding to the predetermined number of sequential characters which were included in a preceding EIN.

11. The method according to claim 4, wherein said acknowledgment block comprises a predetermined sequential arrangement of one or more of a plurality of ACK messages which are addressed to a corresponding one or more of said plurality of RTs, wherein each ACK message comprises:

a preamble including a synchronization character; and

an address which corresponds to a unique RT and which includes at least a portion of the ID of said RT.

12. The method according to claim 11, wherein said sequential arrangement of said plurality of ACK messages is identical to the sequential arrangement of the plurality of messages included in said SDBS signal.

13. The method according to claim 4, wherein said message data block comprises a plurality of variable-length messages concatenated without regard to error-correction block boundaries, each message being directed to selected ones of said plurality of RTs.

14. The method according to claim 4, wherein said reserved redundant group data block comprises a plurality of duplicate error correction blocks which enable the reconstruction of entire data blocks that may be lost in transmission.

15. In a two-way wireless communications system comprising a plurality of base stations (BS) controlled by a computer and a plurality of receiver/transmitters, (RTs), wherein each of said RTs has a unique identification address, a method for transferring data from each of said plurality of RTs to said BS, comprising the steps of:

receiving a serial data bit stream (SDBS) signal comprising an unencoded preamble data packet identifying a unique group address of one or more or said RTs;

a 4 bit Hamming Code for correcting a single byte in the preamble; and

an encoded frame data packet which includes an RT notification data block identifying one or more of said RTs;

processing said SDBS signal by a first decoding means in the RT to determine the presence of a data block specifically addressed to said RT;

determining by a selection means if said RT is required to transmit a message;

creating in said RT, if said RT is required to transmit said message, one or more data blocks, each one of said data blocks being preceded by a fixed frequency tone having a finite duration and each of said data blocks being encoded by an error correction means;

transmitting each one of said data blocks at a predetermined time on a predetermined frequency; and

,

receiving said plurality of data blocks by said BS as a second serial data bit stream (SSDBS) signal.

16. The method according to claim 15, wherein the first decoding means comprises the steps of:

processing a first portion of said SDBS signal to determine the presence of an inactivation code;

terminating for a predetermined time period the processing of said SDBS signal by any ones of said plurality of RTs which did receive said inactivation code;

processing a second portion of said SDBS signal using an error correction algorithm to un-encode the data land to determine the presence of an ID corresponding to a particular one RT from said plurality of RTs;

terminating the processing of said SDBS signal by any ones of said plurality of RTs which did not receive said ID; and

processing the entirety of the second portion of said SDBS signal in each one of said plurality of RTs that have not terminated the processing of said SDBS signal.

17. The method according to claim 15, wherein said selection means comprises a method for determining which ones of said plurality of RTs is required to transmit one or more of a plurality of data blocks from a group comprising:

a prioritized emergency slot data packet if said RT has a pend prioritized emergency message to be sent;

an acknowledgement data packet comprising an acknowledgement messages containing an error status signal corresponding to a message included in said SDBS s if said message was addressed to said RT;

previous message data packet if said RT received a re-transmit command in said SDBS signal;

a message data packet if said RT received a command to transmit data in said SDBS signal;

a message data packet if said RT received an approval to transmit in said SDBS signal; and

a reverse link Free-for-all (FFA) data packet wherein a message requesting transmission time allocation is randomly placed at a time location within the packet if said RT requires such a transmission allocation.

18. The method according to claim 15, wherein said SSDBS signal comprises:

a prioritized emergency data packet;

an acknowledgement (ACK) data packet;

a scheduled message data packet;

a reverse link Free-For-All (FFA) data packet; and

a optional registration data packet.

19. The method according to claim 18, wherein said prioritized emergency data packet comprises a plurality of time periods (E-slots) each having a data size corresponding to a data block size required by said error-correction means, each E-slot being used for an alarm signal that is initiated by the RT when an alarm condition exists.

20. The method according to claim 19, wherein each of said E-slot comprises an ID of the RT initiating the alarm and an optional message.

21. The method according to claim 20, wherein said optional message includes one or more from the;

group comprising;

a request for scheduled transmission time to transmit a message having a size larger than the fixed time periods of the E-slot;

a report describing the alarm; and

a report describing and extended string of alarm conditions or messages.

22. The method according to claim 19, wherein the number of said E-slots can be dynamically changed by said computer.

23. The method according to claim 18, wherein simultaneous transmissions of an emergency alarm in a same E-slot by two or more RTs from said plurality of RTs are sensed by a detection means in said BS and corrected by a method comprising the steps of:

transmitting by the BS a plurality of group messages selectively configured to quickly elicit a response from only the RTs that are transmitting priority emergency alarms in that particular E-slot;

receiving the group messages;

determining by each one of said RTs if said RT is a deduced RT;

transmitting a randomly placed acknowledgment (ACK) message by only the deduced RTs;

transmitting by the BS a SDBS signal which includes scheduled transmission times to said acknowledging RTs;

receiving the scheduling transmission times messages; and

transmitting the alarm messages by said RTs using a controlled non-colliding method.

24. The method according to claim 23, wherein said detection means comprises an algorithm in a corresponding RRM, which determines that a received signal strength is sufficiently greater than a received signal strength of a single signal, such that an E-slot message collision has occurred and that correcting methods should be invoked.

25. The method according to claim 18, wherein said ACK data packet comprises a sequential ordering of ACK messages according to the message sequence of said SDBS signal, and wherein each ACK data packet comprises:

a preamble including a synchronization character;

the last 4 digits of said RT EIN; and

an ACK message indicating an ACK for a satisfactory reception of a message in said SDBS or a non-acknowledgement (NAK) for a unsatisfactory reception of said message.

26. The method according to claim 18, wherein said ACK data packet can have a zero byte data length, whereby a scheduled transmission of data by a unique one of said plurality of RTs corresponds to an ACK of said SDBS message.

27. The method according to claim 18, wherein said scheduled message data packet comprises a plurality of data blocks, each data block being transmitted by a selected RT according to one of a plurality of transmission scheduling data signals included in said SDBS signal, each said data blocks being partitioned into one or more sub-blocks having a size corresponding to a size required by said error correction means.

28. The method according to claim 18, wherein said registration data packet comprises a 33 millisecond preamble and a data block which includes a request for a change in operating channels or a change in BSs in the communications system.

29. The method according to claim 18, wherein said registration data packet is transmitted at a randomly calculated time in a predetermined time period specifically allocated for registration transmissions by said computer.

30. The method according to claim 29, wherein said randomly calculated time in the registration data packet is 100 milliseconds in duration.

31. In a two way wireless communications system comprising a base station (BS) and a plurality of receiver/transmitters (RTs), each of said RTs sending an emergency signal when an emergency condition is detected, a method for determining that first and second emergency messages have been received simultaneously from a first and second one of said plurality of RTs and causing said first and second RTs to resend said first and second messages at different times comprising the steps of:

receiving a signal at said BS;

determining by said BS that the signal strength of said signal during a transmission time slot is greater than a signal strength of a single RT transmission signal;

transmitting by said BS a plurality of group messages requesting a response from only RTs that are transmitting priority emergency alarms in said transmission time slot;

receiving by said plurality of RTs said group messages;

transmitting an acknowledgement (ACK) message to said BS by only said RTs that transmitted an emergency alarm in said time slot;

transmitting by said BS a signal including scheduled transmission times to said acknowledging RTs; and

transmitting the alarm messages by each of said RTs in a controlled non-colliding manner at the corresponding scheduled transmission time.

32. A two-way wireless communications system for transferring data from one or more of a plurality of base station to one or more of a plurality of receiver/transmitters each having a unique identification address, said system further comprising:

a computer for controlling said base stations;

a radio resource manager associated with each base station for controlling a single frequency in its associated base station;

means for creating a plurality of serial data bit stream signals in said computer, each of said serial data bit stream signals comprising an unencoded preamble data packet identifying a unique group address of one or more of said receiver/transmitters;

a four-bit Hamming Code for correcting a single byte in the preamble; and

, an encoded frame data packet which includes receiver/transmitters notification data block;

means for transferring each one of said plurality of serial data bit stream signals to one of said radio resource managers;

means for transmitting said plurality of serial data bit stream signals;

means for receiving said serial data bit stream signals in each of said receiver/transmitters; and

,

means for decoding said encoded frame data packet of a signal only in receiver/transmitters identified in said notification data block.

33. In a two-way wireless communication system for transferring data from one or more of a plurality of receiver/transmitters to one or more of a plurality of base stations said system comprising:

a plurality of said base stations controlled by a computer and a plurality of said receiver/transmitters wherein each of said receiver/transmitters has a unique identification address; and

means for receiving a serial data bit stream signal comprising an unencoded preamble data packet identifying a unique group address of one or more of said receiver/transmitters;

a four-bit Hamming Code for correcting a single byte in said preamble; and

, an encoded frame data packet which includes a receiver/transmitters notification data block identifying one or more of said receiver/transmitters;

means for processing said serial data bit stream signal by a first decoding means in a given receiver/transmitter to determine the presence of a data block specifically addressed to said given receiver/transmitter;

a selection means for determining if said receiver/transmitters is required to transmit a message;

means for creating in a given receiver/transmitter, if said given receiver/transmitter is required to transmit a message, one or more data blocks, each one of said data blocks being preceded by a fixed frequency tone having a finite duration and each of said data blocks being encoded by an error correction means;

means for transmitting each one of said data blocks at a predetermined time on a predetermined frequency; and

means for receiving said plurality of data blocks by said base station as a second serial data bit stream signal.