Multi-mode TDMA spread spectrum communication system

• US 5,787,076 A
• Filed: 02/18/1997
• Issued: 07/28/1998
• Est. Priority Date: 11/01/1993
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Omnipoint Corp. (Deutsche Telekom AG)
• Inventors: Peterson, Peter O., Jensen, Ryan N., Anderson, Gary B., Petch, Bryan K.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): VU, HUY DUY
• Application Number:
  US08/801,529
• Time in Patent Office: 525 Days
• Field of Search: 455/54.1, 455/53.1, 455/54.2, 455/33.1, 379/58, 379/59, 379/60, 375/203, 375/343, 375/324, 370/229, 370/230, 370/235, 370/252, 370/253, 370/276, 370/277, 370/278, 370/279, 370/280, 370/281, 370/282, 370/293, 370/294, 370/297, 370/310, 370/328, 370/329, 370/330, 370/336, 370/337, 370/338, 370/339, 370/340, 370/341, 370/345, 370/347, 370/431, 370/432, 370/433, 370/437, 370/442, 370/458, 370/459, 370/464, 370/465, 370/468 , 370/470, 370/472, 370/477
• US Class Current: 370/294
• CPC Class Codes: G10L 19/012 Comfort noise or silence coding
• CPC Class Codes: H04B 7/0805 with single receiver and antenna switching H04B7/0822 takes precedence
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/36 : with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/362 : Aspects of the step size
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/38 : TPC being performed in particular situations
• CPC Class Codes: H04W 52/40 : during macro-diversity or soft handoff
• CPC Class Codes: H04W 72/0446 : Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/20 : Control channels or signalling for resource management
• CPC Class Codes: H04W 74/06 : using polling
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 92/12 : between access points and access point controllers

Abstract

A simple and flexible over-air protocol for use with a mobile telephone system, having hand-held telephones in a microcell or other type of cellular communication system. A method in which user stations communicate with one or more base stations to place and receive telephone calls, in which the user stations are provided a secure voice or data link and have the ability to handoff calls between base stations while such calls are in progress. Each base station has a set of "air channels" to which it transmits in sequence. The air channels supported by each base station are called that base station'"'"'s "polling loop". A user station receives general polling information on an unoccupied air channel, transmits responsive information to the base station, and awaits acknowledgment from the base station. Each base station may therefore simultaneously maintain communication with as many user stations as there are air channels in its polling loop. The ability of a user station to communicate on any unoccupied air channel makes the protocol air-channel agile, while the stability of user station and base station clocks may define air channels, gaps, and minor frames.

Claims

1. A multi-mode time division multiple access communication system, comprising:

a major time frame, said major time frame repeating periodically,

a plurality of minor time frames in said major time frame, each of said minor time frames comprising a base station transmission allocation and a user station transmission allocation, said base station transmission allocation and said user station transmission allocation collectively comprising more than half of a minor time frame,

a base station including a base station transmitter operating at a data bit transmission rate,

a plurality of user stations each including a user station transmitter operating at said data bit transmission rate, and each of which communicates in at least one of said minor time frames,

wherein communication in each of said minor time frames is carried out in one of a plurality of modes selected independently for each minor time frame, said plurality of modes comprising at least a first mode, a second mode, and a third mode, and

wherein communication according to said first mode is characterized by a first fixed base station transmission allocation equal to a first fixed user station transmission allocation for each periodic repetition of said major time frame until completion of a call, wherein communication according to said second mode is characterized by a second fixed base station transmission allocation not equal to a second fixed user station transmission allocation for each periodic repetition of said major time frame until completion of a call, and wherein communication according to said third mode is characterized by a single direction link transmission with no reverse link transmission.

2. The multi-mode time division multiple access communication system of claim 1 wherein said first mode comprises a symmetric mode, said second mode comprises an asymmetric mode, and said third mode comprises a broadcast mode.

3. The multi-mode time division multiple access communication system of claim 1 wherein data communicated in said first mode comprises voice traffic.

4. The multi-mode time division multiple access communication system of claim 1 wherein said second user station transmission allocation exceeds said second base station transmission allocation.

5. The multi-mode time division multiple access communication system of claim 1 wherein said second user station transmission allocation is less than said second base station transmission allocation.

6. The multi-mode time division multiple access communication system of claim 1 wherein data communicated in said second mode comprises enhanced voice data, video data, or fax data.

19. The multi-mode time division multiple access communication system of claim 1 wherein said base station transmission allocation and said user station transmission allocation are adjacent in time.

20. The multi-mode time division multiple access communication system of claim 1 wherein said base station transmitter and said user station transmitter transmit over the same frequency band.

23. The multi-mode time division multiple access communication system of claim 1 wherein, when in said third mode, said single direction link transmission substantially comprises traffic messages.

7. A multi-mode time division multiple access communication system, wherein a major time frame is divided into a plurality of minor time frames, said system comprising:

a base station including a base station transmitter operating at a data bit transmission rate, said base station communicating in at least one fixed-length base station transmission time period within a minor time frame,

a plurality of user stations each including a user station transmitter operating at said data bit transmission rate, and each of which communicates in at least one fixed-length user station time period within a minor time frame, said base station transmission time period and said user station time period collectively comprising more than half of a minor time frame, and

a plurality of modes by which the relative lengths of said base station transmission time period and said user station transmission time period are allocated on a continuing basis over a plurality of consecutive major time frames, said plurality of modes comprising a symmetric mode in which said user station transmission time period is equal in length to said base station transmission time period for each of said plurality of consecutive major time frames, an asymmetric mode in which said user station transmission time period is unequal in length to said base station transmission time period for each of said plurality of consecutive major time frames, and a broadcast mode in which no user station transmission time period is designated for each of said plurality of consecutive major time frames.

8. The multi-mode time division multiple access communication system of claim 7 wherein said broadcast mode is characterized by a base station transmission without a reverse link user station transmission, said base station transmission being intended for receipt by a plurality of said user stations.

9. The multi-mode time division multiple access communication system of claim 7 wherein said user station transmission time period exceeds said base station transmission time period in said asymmetric mode.

10. The multi-mode time division multiple access communication system of claim 7 wherein said user station transmission time period is less than said base station transmission time period in said asymmetric mode.

11. The multi-mode time division multiple access communication system of claim 7 wherein data communicated in said symmetric mode comprises voice traffic.

12. The multi-mode time division multiple access communication system of claim 7 wherein data communicated in said asymmetric mode comprises enhanced voice data, video data, or fax data.

21. The multi-mode time division multiple access communication system of claim 7 wherein said base station transmission time period and said user station transmission time period are time-adjacent.

22. The multi-mode time division multiple access communication system of claim 7 wherein said base station transmitter and said user station transmitter transmit over the same frequency band.

24. The multi-mode time division multiple access communication system of claim 7 wherein, when in said broadcast mode, messages transmitted during said base station transmission time period include non-signaling traffic messages.

13. A method comprising the steps of:

establishing a series of major time frames, each major time frame divided into a plurality of minor time frames,

selecting for each minor time frame used for communication a mode from among a plurality of modes for subsequent communication, said plurality of modes comprising at least a symmetric mode and an asymmetric mode,

dividing each minor time frame for which said symmetric mode is selected into two substantially equal fixed portions for duplex bearer traffic communication between a base station and a user station to which the minor time frame is assigned, and

dividing each minor time frame for which said asymmetric mode is selected into two unequal fixed portions for duplex bearer traffic communication between said base station and a user station to which the minor time frame is assigned, one of said two unequal fixed portions having a first predefined duration regardless of voice activity and the other of said two unequal fixed portions having a second predefined duration regardless of voice activity.

14. The method of claim 13 further comprising the step of communicating between said base station and each user station using spread spectrum communication.

15. The method of claim 13 wherein said plurality of modes further comprises a broadcast mode, and further comprising the step of transmitting a broadcast transmission from said base station in each minor time frame for which said broadcast mode is selected without receiving a corresponding reverse link transmission at said base station.

25. The method of claim 15 wherein said step of transmitting a broadcast transmission from said base station in each minor time frame for which said broadcast mode is selected comprises the step of transmitting at least some traffic messages during at least one minor time frame for which said broadcast mode is selected.

16. A time division multiple access communication system comprising:

a repeating series of major time frames, each major time divided into a plurality of minor time frames of substantially the same length, and

a base station capable of communicating with a plurality of user stations, said base station operating in one of a plurality of different modes in each minor time frame, one of said plurality of different modes being assigned to each minor time frame to govern ongoing communication within that minor time frame regardless of voice activity,

said different modes including a first mode wherein two fixed equal portions of a minor time frame are allocated to base station bearer traffic messages and user station bearer traffic messages, a second mode wherein two fixed unequal portions of a minor frame are allocated to base station bearer traffic messages and user station bearer traffic messages, one said two fixed unequal portions being of a first predefined duration and the other of said two fixed unequal portions being of a second predefined duration, and a third mode wherein the entirety of the time frame is allocated to said base station.

17. The time division multiple access communication system of claim 16 wherein said base station transmits and receives messages using spread spectrum communication.

18. The time division multiple access communication system of claim 16 wherein said base station and said user stations transmit data at the same bit rate.

26. A method of communication, comprising the steps of:

establishing a major time frame, said major time frame repeating periodically;

establishing a plurality of minor time frames in said major time frame for communication between a base station and a plurality of user stations;

allocating, on demand, minor time frames to user stations, such that each user station communicating with said base station communicates in the same minor time frame with each periodic repetition of said major time frame;

selecting, for each minor time frame allocated to a user station, a communication mode from among a plurality of communication modes, said plurality of communication modes including at least a symmetric mode and an asymmetric mode;

allocating, for each minor time frame for which said symmetric mode is selected, a first user-to-base transmission time period and a first base-to-user transmission time period for all subsequent communication, said first user-to-base transmission time period and said first base-to-user transmission time period being of substantially equal duration;

allocating, for each minor time frame for which said asymmetric mode is selected, a second user-to-base transmission time period and a second base-to-user transmission time period for all subsequent communication, said second user-to-base transmission time period and said second base-to-user transmission time period being unequal in duration and having the same fixed length at each occurrence of the minor time frame;

for each minor time frame for which said symmetric mode is selected, at each periodic repetition of said major time frame and regardless of voice activity detection, transmitting user-to-base messages from the user station to which the minor time frame is allocated to said base station only during said first user-to-base transmission time period, and transmitting base-to-user messages from said base station to the user station to which the minor frame is allocated only during said first base-to-user transmission time period; and

for each minor time frame for which said asymmetric mode is selected, at each periodic repetition of said major time frame and regardless of voice activity detection, transmitting user-to-base messages from the user station to which the minor time frame is allocated to said base station only during said second user-to-base transmission time period, and transmitting base-to-user messages from said base station to the user station to which the minor frame is allocated only during said second base-to-user transmission time period.