Modulary clustered radiotelephone system

• US 6,208,630 B1
• Filed: 12/21/1998
• Issued: 03/27/2001
• Est. Priority Date: 09/30/1993
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Vessal, David, Cooley, David M., Lemmo, Mark A., Kaewell, John D., Regensburg, Michael W., Kurtz, Scott D., DiGiovanni, Joseph J., Johns, Eric
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/217,640
• Time in Patent Office: 827 Days
• Field of Search: 370/324, 370/328, 370/329, 370/336, 370/341, 370/343, 370/344, 370/347, 370/442, 370/458, 370/330, 370/337, 370/484, 375/222
• US Class Current: 370/330
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 74/0891 for synchronized access
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 88/00 Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
• CPC Class Codes: H04W 88/021 adapted for Wireless Local Loop operation
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A power-conserving time division multiple access (TDMA) radio telephone system is disclosed in which a cluster of subscriber stations, remote from a base station, employs a common pool of frequency-agile modems each of which digitally synthesizes, on a timeSlot-by-timeSlot basis, the different channel-identifying intermediate frequencies needed to support communications between several of the subscriber stations and the base station. Power conservation is facilitated inter alia by controlling the assignment of modems to calls, maintaining unassigned modems in a powered-down state and by controlling the number of calls using the same time slot. Delay in assigning a powered-down modem to a call is eliminated by making available to all modems the highest quality synchronization information obtained by any of the active modems.

Claims

1. A radio telephone system for supporting communications between a base station and a plurality of remote subscriber stations on repetitive time slots of high frequency radio channels comprising:

a group of modems assignable to said subscriber stations, each of said modems being capable of digitally synthesizing, modulating and demodulating a plurality of channel-identifying intermediate frequencies on successive ones of said repetitive time slots to simultaneously handle a number of communications during successive time slots;

means for sending and receiving said channel-identifying intermediate frequencies between said base station and said subscriber stations;

means for upwardly block converting all of said intermediate frequencies produced by said group of modems to said high frequency radio channels; and

means for downwardly block converting said high radio frequency channels to a plurality of modulated channel-identifying intermediate frequencies.

2. A radio telephone system according to claim 1 wherein said modems are each capable of digitally synthesizing a different one of said channel identifying intermediate frequencies on a plurality of successive time slots.

3. A method of supporting communications in a radio telephone system between a base station and a plurality of remote subscriber stations on repetitive time slots of high frequency radio channels comprising the steps of:

assigning a group of modems to said subscriber stations;

digitally synthesizing, modulating, and demodulating of channel-identifying intermediate frequencies on successive ones of said repetitive time slots by anyone of said group of modems;

simultaneously handling a number of communications between said base station and said subscriber stations by using successive time slots;

sending and receiving said channel-identifying intermediate frequencies between said base station and said subscriber stations;

upwardly block converting all of said intermediate frequencies by said group of modems to said high frequency radio channels; and

downwardly block converting said high radio frequency channels by said group of modems to a plurality of modulated channel-identifying intermediate frequencies.

4. A method according to claim 3 wherein anyone of said group of modems has the capacity of switching to and using a different one of said channel identifying intermediate frequencies on a plurality of successive time slots.