Method and system for data link expansion or contraction using spread spectrum TDMA communication

• US 5,818,820 A
• Filed: 06/07/1995
• Issued: 10/06/1998
• Est. Priority Date: 11/01/1993
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Omnipoint Corp. (Deutsche Telekom AG)
• Inventors: Anderson, Gary B., Peterson, Peter O.
• Primary Examiner(s): SAFOUREK, BENEDICT V
• Application Number:
  US08/478,384
• Time in Patent Office: 1,217 Days
• Field of Search: 375/200, 375/205, 370/18, 370/24, 370/29, 370/84, 370/85.7, 370/95.1, 370/95.3, 370/321, 370/322, 370/329, 370/336, 370/337, 370/347, 370/348, 370/442, 370/443, 370/468, 370/280, 370/281 , 370/294, 370/295, 455/450, 455/452
• US Class Current: 370/280
• 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 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• 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 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 72/044 : based on the type of the allocated resource
• 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 76/10 : Connection setup
• 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 micro cell 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.

In a preferred embodiment, a user station may communicate at an increased data rate by acquiring and communicating in multiple time slots that are either contiguous or non-contiguous within a time frame, or may communicate at a reduced data rate by communicating in alternating time frames or every N time frames.

Claims

1. A time division multiple access communication system supporting different data rates, comprising:

a time division multiple access protocol according to which each of a plurality of major time frames is divided into a plurality of minor time frames, each of said plurality of minor time frames being freely allocable and of uniform duration, and each minor time frame having a forward link transmission interval and a reverse link transmission interval for supporting time division duplex communication,

a base station, and

a plurality of user stations capable of communicating with said base station using said time division multiple access protocol, wherein a number of minor time frames is assigned to each user station in communication with said base station according to a bandwidth demand, said minor time frames being assigned without regard to their relative positions within a major time frame.

2. The time division multiple access communication system of claim 1 wherein said base station and said user stations communicate using direct sequence spread spectrum communication.

3. The time division multiple access communication system of claim 1, wherein each minor time frame is either symmetric or asymmetric, and wherein the forward link transmission interval of a symmetric minor time frame is equal in time allocation to its reverse link transmission interval, and the forward link transmission interval of an asymmetric minor time frame is unequal in time allocation to its reverse link transmission interval.

4. A time division multiple access communication system comprising:

a time division multiple access protocol according to which each of a plurality of major time frames is divided into a plurality of minor time frames, each of said plurality of minor time frames being freely allocable and of uniform duration, and each minor time frame having a forward link transmission interval and a reverse link transmission interval,

a base station, and

a plurality of user stations capable of communicating with said base station in assigned minor time frames, each user station operating in one of a plurality of user station modes,

wherein a first one of said plurality of user station modes is characterized by communication with said base station in a plurality of minor time frames in each major time frame, said minor time frames being made available for communication in said first user station mode without regard to their relative positions within the major time frame, a second one of said plurality of user station modes is characterized by communication with said base station in a single minor time frame in each major time frame, and a third one of said plurality of user station modes is characterized by communication with said base station in fewer than one minor time frame in each major time frame.

5. The time division multiple access communication system of claim 4 wherein said base station and said user stations communicate using direct sequence spread spectrum communication.

6. The time division multiple access communication system of claim 4 wherein each minor time frame is of a duration sufficient to support full duplex voice communication between said base station and a single user station.

7. The time division multiple access communication system of claim 4 wherein a user station operating in said first user station mode transmits video data or facsimile data at a higher data rate than necessary to transmit voice data.

8. The time division multiple access communication system of claim 4 wherein a user station operating in said second user station mode and said base station are capable of transmitting up to eight kilobits of information per second each direction in full duplex communication.

9. A time division multiple access communication system comprising:

a base station,

a plurality of user stations communicating with said base station according to a time division multiple access communication protocol,

a repetitive major time frame generated according to said time division multiple access communication protocol,

a plurality of minor time frames in said major time frame, each of said minor time frames being freely allocable and of uniform duration

a user-to-base transmission interval in each of said minor time frames, during which the user station to which the minor time frame is assigned transmits user-to-base messages to the base station,

a base-to-user transmission interval in each of said minor time frames, during which the base station transmits base-to-user messages to the user station to which the minor time frame is assigned, and

means for assigning minor time frames among a plurality of user stations, whereby a maximum data rate for communication between each user station and a base station is determined by a number of minor time frames assigned to the user station, said minor time frames being assigned according to user demand without regard to location within said major time frame.

10. The time division multiple access communication system of claim 9 wherein communications between said base station and said user stations are encoded using a direct sequence spread spectrum technique.

11. The time division multiple access communication system of claim 9 wherein said means for assigning minor time frames among said plurality of user stations comprises a bandwidth request message from a user station to said base station.

12. A method comprising the steps of:

generating a repetitive major time frame at a base station;

generating a series of minor time frames within each major time frame, each of said minor time frames being freely allocable and of uniform duration, and each minor time frame comprising a base-to-user transmission interval and a user-to-base transmission interval;

assigning, on demand, a first plurality of minor time frames to a first plurality of user stations, one minor time frame for each of said first plurality of user stations; and

assigning, on demand, a second plurality of minor time frames to a single user station not within the group of said first plurality of user stations, said second plurality of minor time frames being assigned without regard to the relative locations of said minor time frames within a major time frame.

13. The method of claim 12 wherein said first plurality of minor time frames and said second plurality of minor time frames are assigned in response to a user-initiated request occurring during each of the available minor time frames for which assignment is sought by the user station.

14. The method of claim 12 further comprising the step of assigning, on demand, one of said minor time frames to a sub-rate user station for communication in every other major time frame or a less frequent basis, said one minor time frame not in the group of said first plurality of minor time frames or said second plurality of minor time frames.

15. The method of claim 12 further comprising the step of transmitting direct sequence spread spectrum messages between said base station and said user stations during the assigned minor time frames.

16. The method of claim 12, further comprising the step of designating each assigned minor time frame as being either symmetric or asymmetric, such that the user-to-base transmission interval of an assigned minor time frame designated as symmetric is equal in time allocation to its base-to-user transmission interval, and the user-to-base transmission interval of an assigned minor time frame designated as asymmetric is unequal in time allocation to its base-to-user transmission interval.

17. A method of wireless communication, comprising:

establishing a repeating major time frame;

establishing, in each major time frame, a plurality of minor time frames of uniform duration, each minor time frame being freely allocable and each comprising a user-to-base transmission interval and a base-to-user transmission interval;

assigning, on demand, and without regard to relative position within the major time frame, a minor time frame to each of a plurality of user stations requesting communication with a cellular base station, such that each user station transmits messages to the cellular base station in the user-to-base transmission interval of the assigned minor time frame and receives messages from the cellular base station in the base-to-user transmission interval of the assigned minor time frame;

assigning, on demand, and without regard to relative position within the major time frame, additional minor time frames to a user station so requesting, such that a user station with multiple assigned minor time frames transmits messages to the cellular base station in the user-to-base transmission interval of each assigned minor time frame and receives messages from the cellular base station in the base-to-user transmission interval of each assigned minor time frame; and

designating each assigned minor time frame as being either symmetric or asymmetric, such that the user-to-base transmission interval of an assigned minor time frame designated as symmetric is equal in time allocation to its base-to-user transmission interval, and the user-to-base transmission interval of an assigned minor time frame designated as asymmetric is unequal in time allocation to its base-to-user transmission interval.

18. The method of claim 17, further comprising the step of transmitting both control signaling information and bearer traffic messages using the same minor time frame.

19. A wireless, cellular communication system, comprising:

a base station;

a plurality of user stations; and

a time division duplex protocol according to which a repeating major time frame is divided into a plurality of freely allocable minor time frames of uniform duration, each minor time frame having a base-to-user transmission interval and a user-to- base transmission interval for supporting time division duplex communication between said base station and one of said user stations;

wherein said minor time frames are assigned to said user stations on demand and without regard to their relative positions within the major time frame;

wherein a user station transmits user-to-base messages during the user-to-base transmission interval of each minor time frame assigned to it, and receives base-to-user messages during the base-to-user transmission interval of each minor time frame assigned to it; and

wherein each assigned minor time frame is designated as either symmetric or asymmetric, such that the user-to-base transmission interval of a minor time frame designated as symmetric is equal in time allocation to its base-to-user transmission interval, and the user-to-base transmission interval of a minor time frame designated as asymmetric is unequal in time allocation to its base-to-user transmission interval.

20. The wireless communication system of claim 19, wherein any minor time frame can be used for transmitting both control signaling information and bearer traffic messages.