Method and apparatus for allocating time slots within a frame of a TDMA frequency channel

• US 7,133,418 B1
• Filed: 12/04/1997
• Issued: 11/07/2006
• Est. Priority Date: 12/06/1996
• Status: Expired due to Fees

• Current Assignee: Inmarsat Global Limited (Inmarsat PLC)
• Original Assignee: Inmarsat Global Limited (Inmarsat PLC)
• Inventors: Harper, John Anthony, Macridis, Philip
• Primary Examiner(s): NGUYEN, DAVID Q
• Assistant Examiner(s): Perez-Gutierrez, Rafael
• Application Number:
  US09/319,460
• Time in Patent Office: 3,260 Days
• Field of Search: 370/468, 370/458, 370/337, 370/347, 370/336, 370/345, 370/348, 370/442, 370/238, 370/238.1, 370/235, 370/230, 370/326, 370/329, 370/444, 370/443, 370/461, 370/465, 370/498, 370/508, 455/450, 455/452, 455/453, 455/509, 455/512
• US Class Current: 370/468
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04B 7/18545 Arrangements for managing station mobility, i.e. for station registration or localisation
• CPC Class Codes: H04B 7/1858 Arrangements for data transmission on the physical system, i.e. for data bit transmission between network components
• CPC Class Codes: H04J 3/1682 Allocation of channels according to the instantaneous demands of the users, e.g. concentrated multiplexers, statistical multiplexers
• CPC Class Codes: H04L 2012/5607 Radio
• CPC Class Codes: H04L 2012/5608 Satellite
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5632 Bandwidth allocation
• CPC Class Codes: H04L 2012/5634 In-call negotiation
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 4/00 Services specially adapted for wireless communication networks; Facilities therefor
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185

Abstract

A satellite communications system provides a communications service to a mobile terminal on which different communications applications may be run. Calls are set up between any of the applications via a satellite to a network management center which provides different service adaptors which adapt the calls to different types of service provided over terrestrial networks such as telephony, facsimile, internet or ATM services. The bandwidth allocated to each call over the satellite link may be varied during the call according to demand either from the relevant application or from the network management center. Multiple calls may be connected concurrently to or from different applications running on the mobile terminal. A maximum bandwidth is allocated to each call. Efficient use is thereby made of the limited bandwidth available over the satellite, according to the instantaneous bandwidth requirements of different applications. For real-time calls requiring multiple slots per frame in a TDMA channel, the slots are mutually spaced apart to reduce delay.

Claims

1. Apparatus for assigning time slots within a TDMA frame of a frequency channel to a plurality of calls between a base station and one or more mobile terminals, said calls being either real-time time calls or non real-time time calls which have less sensitivity to delay then real-time time calls and comprising at least one real-time call requiring a plurality of time slots per frame;

the apparatus comprising;

means for determining which of said plurality of calls are real-time calls requiring allocation of a plurality of time slots in said TDMA frame; and

means for allocating said time slots in said frame to said real-time calls such that the plurality of time slots allocated to each of said real-time time calls are mutually spaced apart in said TDMA frame in said frequency channel.

2. Apparatus as claimed in claim 1, wherein said means for allocating are further arranged to allocate one or more time-slots to each of said non real-time time calls from the time slots in said frame not allocated to each of said real-time calls, a number of said time slots allocated to said non real-time call being variable during said non real-time call according to a current bandwidth allocation for said non real-time call.

3. Apparatus as claimed in claim 1 or 2, further comprising means for transmitting call signals in said time slots in accordance with the allocation of said time slots.

8. A method as claimed in any preceding claim, further comprising allocating one or more time slots to each of said non real-time calls from the time slots in said frame not allocated to each of said real-time calls, a number of said time slots allocated to said non real-time call being variable during said non real-time call according to a current bandwidth allocation determined for said non real-time call.

4. The apparatus as claimed in claimed 1, wherein at least one of the real-time calls comprises a voice call.

5. A method of assigning time slots within a TDMA frame of a frequency channel to a plurality of calls between a base station and one or more mobile terminals, said calls being either real-time calls or non real-time calls and comprising at least one real-time call requiring a plurality of time slots per frame;

the method comprising;

determining which of said plurality of calls are real-time calls requiring allocation of a plurality of time slots in said TDMA frame; and

allocating said time slots in said frame to said real-time calls such that the plurality of time slots allocated to each of said real-time call are mutually spaced apart in said TMDA frame in said frequency channel.

6. A method as claimed in claim 5, wherein said TDMA frequency channel is a return channel for communication from said one or more mobile terminals to said base station, the method further comprising:

transmitting to said one or more mobile terminals information relating to the allocation of said time slots in the return channel, such that call signals are transmitted by said one or more mobile terminals in said allocated slots of the return channel.

7. A method as claimed in claim 5, wherein said TDMA frequency channel is a forward channel for communication from said base station to said one or more mobile terminals, the method further comprising transmitting call signals in said time slots in accordance with the allocation of said time slots.

9. The method as claimed in claim 5, wherein at least one of the real-time calls comprises a voice call.