Modularly clustered radiotelephone system

• US 6,496,488 B1
• Filed: 11/02/2000
• Issued: 12/17/2002
• Est. Priority Date: 09/30/1993
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Cooley, David M., Lemmo, Mark A., Kaewell, John D., Regensburg, Michael W., Kurtz, Scott D., DiGiovanni, Joseph J., Johns, Eric, Vessal, David
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/704,318
• Time in Patent Office: 775 Days
• Field of Search: 370/321, 370/324, 370/328, 370/329, 370/336, 370/337, 370/347, 370/350, 370/330, 375/222
• US Class Current: 370/324
• 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 having a base station and a modular subscriber cluster, where a plurality of physically adjacent subscribers share a common pool of frequency agile modems, comprising:

means for defining a repetitive set of time slots for signal transmission;

said cluster tracking and assigning a priority to all available time slots of said common pool modems;

said cluster selecting one of available time slots based on the assigned priority; and

said cluster through a plurality of channel identifying frequencies synchronizing said selected time slot of a selected one of said common pool modems to a selected time slot of a plurality of received time slots.

2. A radiotelephone system according to claim 1 wherein said cluster assigns the priority by setting higher priority to all of said set of time slots to one of said common pool modems before assigning a time slot to any remaining ones of said modems.

3. A radiotelephone system according to claim 2 wherein said remaining ones of said modems reside in a powered-down state until assigned to a time slot by said cluster.

4. A radiotelephone system according to claim 1 wherein said cluster includes means for synchronizing said modems with said base station.

5. A radiotelephone system according to claim 4 wherein said cluster includes means for sequentially directing certain of said plurality of modems to search through said channel-identifying frequencies during one of said time slots.

6. A radiotelephone system according to claim 2 wherein said selected one of said common pool modems provides synchronization information to said remaining ones of said common pool modems.

7. A radiotelephone system according to claim 6 wherein certain of said modems compute a respective set of synchronization parameters, wherein cluster said cluster ascertains the reliability of said respective sets of synchronization parameters, and wherein said cluster identifies said one of said modems to deliver said synchronizing information to the remaining ones of said modems.