TDMA messaging service microcell

• US 7,280,503 B2
• Filed: 10/03/2005
• Issued: 10/09/2007
• Est. Priority Date: 06/28/1996
• Status: Expired due to Fees

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: Cingular Wireless II LLC (AT&T, Inc.)
• Inventors: Amin, Umesh J., Buhrmann, Michael
• Primary Examiner(s): Levitan; Dmitry
• Application Number:
  US11/243,392
• Publication Number:
  US 20060029019A1
• Time in Patent Office: 736 Days
• Field of Search: 370/328, 370/329, 370/336, 370/337, 370/345, 370/347, 370/313, 370/314, 455/450, 455/507, 455/504, 455511-517, 455/466
• US Class Current: 370/329
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A cellular messaging network includes a switching controller connected to the wireless telephone network. One or more base station micro/picocell retransmitters are coupled to the switching controller. The base station micro/picocell transmitter uses simplified control equipment having no digital traffic channel capability. Each base station micro/picocell retransmitter is able to discriminate between voice channel assignment signals and short messaging signals in the digital control channel, discard the voice channel assignment signals, and rebroadcast the short messaging signals in the digital control channel. One or more receivers are coupled to the base station micro/picocell retransmitters by way of an IS-136 protocol digital control channel. The base station micro/picocell retransmitter can be connected to the switching controller through a twisted-pair telephone line.

Claims

1. A method of receiving a message on a digital control channel for use in a cellular messaging network, comprising the following steps:

(A) receiving voice channel assignment signals related to the assignment of voice channels and short messaging signals based on the message from the digital control channel;

(B) distinguishing between the voice channel assignment signals and the short messaging signals; and

(C) discarding the voice channel assignment signals.

2. The method of claim 1, wherein:

the voice channel assignment signals and the short messaging signals are time-division multiplexed in the digital control channel.

3. The method of claim 1, wherein step (A) includes the step:

demultiplexing the digital control channel.

4. The method of claim 1, further comprising the step:

paging a receiver in the cellular messaging network using the short messaging signals.

5. A base station retransmitter for use with a digital control channel, comprising:

means for connecting to a switching controller and receiving a modulated carrier signal from the switching controller;

an internal circuit coupled for receiving the modulated carrier signal, the internal circuit comprising;

means for demodulating the modulated carrier signal to generate a multiplexed digital signal,

means for demultiplexing the multiplexed digital signal to generate voice channel assignment signals and short messaging signals, and

means for discarding the voice channel assignment signals.

6. The base station retransmitter of claim 5, wherein:

the multiplexed digital signal is presented as a series of one or more frames.

7. The base station retransmitter of claim 5, further comprising:

a buffer memory coupled to the means for demodulating which is operable to generate the multiplexed digital signal in response to a timing recovery signal.

8. The base station retransmitter of claim 7, further comprising:

a means, coupled to the buffer memory, for generating a timing recovering signal.

9. The base station retransmitter of claim 5, further comprising:

an antenna for broadcasting the short messaging signals.

10. A portable transceiver, comprising:

a receiver configured to receive a multiplexed digital signal including a voice channel assignment subchannel for voice channel assignment signals and a short messaging subchannel for short messaging signals;

a demultiplexer configured to demultiplex the multiplexed digital signal to generate a short messaging signal and a voice channel assignment signal;

a screening circuit configured to screen the voice channel assignment signal from further processing; and

a decoder that decodes the short messaging signal to obtain a message.

11. The portable transceiver of claim 10, wherein the multiplexed digital signal is TDMA signal.

12. The portable transceiver of claim 10, wherein the voice channel assignment subchannel and the short messaging subchannel are time-division multiplexed in the multiplexed digital signal.

13. The portable transceiver of claim 10 wherein the multiplexed digital signal includes a series of one or more frames.

14. The portable transceiver of claim 10, further comprising a transmitter configured to rebroadcast the short messaging signal.

15. A retransmitter for a wireless network, comprising:

a connection configured to receive a modulated carrier signal;

a demodulator configured to demodulate the modulated carrier signal to generate a time-division multiplexed digital signal;

a demultiplexer configured to demultiplex the time-division multiplexed digital signal to generate a short messaging signal and a voice channel assignment signal; and

a screening circuit configured to screen the voice channel assignment signal from further processing.

16. The retransmitter of claim 15, further comprising a decoder configured to decode the short messaging signal to obtain a message.

17. The retransmitter of claim 15, further comprising an antenna, wherein the antenna is configured to direct the modulated carrier signal to the connection.

18. The retransmitter of claim 15, wherein the demodulator is configured to generate an oversampled, demodulated time-division multiplexed digital signal, and further comprising a buffer memory configured to receive the demodulated time-division multiplexed digital signal.

19. The retransmitter of claim 15, further comprising a timing recovery circuit configured to select samples of the time-division multiplexed digital signal from the buffer memory.

20. A portable transceiver, comprising:

a receiver configured to receive a multiplexed digital signal including voice channel assignment signals and short messaging signals; and

a circuit configured to distinguish voice channel assignment signals from short messaging information in the multiplexed digital signal and discard signal portions associated with the voice channel assignment signals.

21. The portable transceiver of claim 20, further comprising a decoder configured to obtain at least one message based on the short messaging information.

22. The portable transceiver of claim 21, further comprising a transmitter configured to transmit a signal based on the short messaging information.

23. The portable transceiver of claim 21, further comprising a decoder configured to obtain a message from the short messaging information that is directed to the portable transceiver.

24. The portable transceiver of claim 23, further comprising a transmitter configured to transmit an acknowledgement message.