Packet transmissions over cellular radio

• US 20030072295A1
• Filed: 12/13/2002
• Published: 04/17/2003
• Est. Priority Date: 12/02/1997
• Status: Abandoned Application

• Current Assignee: Nicholas Frank Maxemchuk
• Original Assignee: Nicholas Frank Maxemchuk
• Inventors: Maxemchuk, Nicholas Frank
• Application Number:
  US10/319,722
• Publication Number:
  US 20030072295A1
• Time in Patent Office: Days
• US Class Current: 370/348
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

An improved system is achieved in a cellular arrangement where mobile units employ a moveable slot TDM approach to send packets to base stations, and where the base stations use a non-contention approach. When a base station transmits information packets to different mobile units, it merely queues the packets and transmits over a given channel. In a corresponding inbound channel, the mobile units transmit packets to the base station using the MSTDM protocol. The base station also transmits information regarding whether the inbound frequency is occupied by a signal that is being transmitted to the base station, or whether a collision exists. A collision on an inbound frequency occurs when more than one signal is simultaneously transmitted on the inbound frequency. On an additional control channel that is shared by all base stations, the base station sends information in a TDM fashion.

Claims

1. A method for communicating comprising the steps of:

a mobile unit that wishes to transmit information in the form of packets, over a first wireless, shared, inbound channel to a non-mobile base station, determines, based on information derived from a second wireless channel that is other than said first wireless channel and logically distinct from a outbound channel by which said mobile unit receives information packets from said non-mobile base, whether the first wireless channel is busy,

when the first wireless channel is busy, the mobile unit refrains from transmitting, and

when the first wireless channel is not busy, the mobile unit transmits a packet of information.

2. The method of claim 1 further comprising the steps of:

when said packet is a data packet, the mobile unit also determines, based on information from said second wireless channel, whether a collision has occurred with a transmission of a packet by some other mobile unit,

when said packet is a data packet and the mobile unit determines the existence of said collision, the mobile unit stops transmitting said packet,

when said packet belongs to a voice source and it is a first packet of said voice source, the mobile unit determines, based on information from said second wireless channel, whether a collision has occurred with a transmission of a packet by some other mobile unit,

when said packet belongs to said voice source and it is a first packet of said voice source, and the mobile unit determines the existence of said collision, the mobile unit stops transmitting said packet, and

when said packet belongs to said voice source and it is other than said first packet of said voice source, the mobile unit transmits the entire packet without determining whether a collision has occurred with a transmission of a packet by some other mobile unit.

3. The method of claim 1 where said information from said second wireless channel is placed on said second wireless channel by said base station.

4. The method of claim 3 where said second wireless channel is embedded in said outbound channel.

5. The method of claim 4 where said information packets sent to said mobile units are data packets, voice packets, or a mixture of both.

6. The method of claim 3 where said information which enables said mobile unit to determine whether said first wireless channel is busy, comprises a first marker which indicates that said first wireless channel becomes busy, and a second marker which indicates that said first wireless channel becomes not busy.

7. The method of claim 3 where said information which enables said mobile unit to determine whether said first wireless channel is busy, comprises a first marker which indicates that said first wireless channel becomes busy with a data packet, and a second marker which indicates that said first wireless channel becomes busy with a voice packet.

8. The method of claims 6 or 7 where said information which enables said mobile unit to determine the existence of a collision condition is a third marker.

9. The method of claim 8 where said markers comprise a data link escape character followed by two bits of information that are injected into a wireless channel that said base station employs for sending information packets to said mobile unit.

10. The method of claim 2 where said mobile unit transmits said data packet in one form of modulation, and transmits packets of said voice source in another form of modulation.

11. The method of claim 10 where said one form of modulation is a suppressed carrier form of modulation, and said another form of modulation is a non-suppressed carrier form of modulation, or said another form of modulation is a suppressed carrier form of modulation, and said one form of modulation is a non-suppressed carrier form of modulation.

12. The method of claim 2 where data packets are shorter than packets from voice sources.

13. A cellular arrangement having mobile units and cells, where each cell covers a roughly circular geographical area by means of a base station at the center of the cell, and where a plurality of cells are arranged to cover a larger geographical area, where each base station comprises:

a receiver,

a transmitter, and

means for informing mobile units of simultaneous detection by said receiver of packets in an inbound frequency channel, said informing being carried out by causing said transmitter to transmit, over a collision detection frequency channel that is distinct from said inbound frequency channel and also distinct from outbound frequency channels that are used by said transmitter to send information packets to said mobile units.

14. The arrangement of claim 13 where the means for informing mobile units also inform the mobile units as to whether the inbound channel is busy.

15. The arrangement of claim 13 where said means for informing mobile units comprises:

apparatus associated with the receiver which detects simultaneous reception over the inbound frequency channel of data packets and voice packets, and

apparatus associated with the transmitter which signals a detection of said simultaneous reception of data packets and voice packets over said collision detection frequency channel.

16. The arrangement of claim 13 where said means for informing mobile units includes apparatus in the receiver that detects simultaneous reception of packets.

17. The arrangement of claim 16 where the apparatus that detects simultaneous reception of packets checks error correcting codes embedded in packets transmitted by mobile units.

18. The arrangement of claim 13 where said transmitter assigns the frequency of the inbound channel, and where the inbound channel and the outbound channel are in a first frequency band that is substantially not overlapping with frequency bands that are employed by transmitters of adjacent cells.

19. The arrangement of claim 18 where transmitters of adjacent cells employ a second frequency band and a third frequency band such that adjacent cells use a different one of said second frequency band and third frequency band.

20. The arrangement of claim 13 where said transmitter also transmits common control information over a frequency that is shared by transmitters of all of said cells, in a time division multiplexing.

21. The arrangement of claim 20 where the time division multiplexing provides for three time channels, and a time channel used by a base station is different from a time channel that is used by an adjacent base station.