| Patent Number |
Title Of Patent |
Date Issued |
| 5475374 |
Method and apparatus for energy conservation in a communication system |
December 12, 1995 |
| A portable radio device (106) has a first operational mode and a second operational mode, and includes a receiver (314), a controller (315), and a mode control device (350). The receiver (314) receives an indexed information message. The controller (315) stores an authorized information |
| 5450617 |
Method and apparatus for closed loop frequency control in a two-way communication system |
September 12, 1995 |
| A method and apparatus for closed loop frequency control in a two-way radio communication system (100) include a base communication unit (104) and a portable communication unit (108) having a portable-to-base initiation channel (202) assigned to a predetermined frequency. A signal is |
| 5398021 |
Reliable information service message delivery system |
March 14, 1995 |
| A method and apparatus for reliably delivering information service messages (300) from a central terminal (106) to a communication receiver (118) in a wireless message communication system (100). The communication receiver (118) receives information service messages including an informat |
| 5343319 |
Apparatus for adapting an electrical communications port to an optical communications port |
August 30, 1994 |
| An apparatus (100) couples first and second electronic devices (206, 202), the first electronic device (206) having an optical communications port (208) and the second electronic device (202) having an electrical communications port (204). The apparatus (100) includes an electrical i |
| 5325088 |
Synchronous selective signalling system |
June 28, 1994 |
| A selective call receiver (111) has a first mask (134A) stored within the selective call receiver (111) indicative of a first period of reception for receiving a transmitted communication signal (99) having a plurality of packets (100). Each of the transmitted packet (100) has message |
| 5252963 |
"Selective call receiver" |
October 12, 1993 |
| In a battery powered selective call receiver receiving a synchronous signal, a battery saving method extends battery life by optimizing the amount of time the receiver circuit is activated when searching for the signal after previously acquiring synchronization. The battery saving me |
| 4964121 |
Battery saver for a TDM system |
October 16, 1990 |
| A power saving method and apparatus in a time division multiplexed system (10) capable of providing a synchronous full duplex communication between a telephone network (12) and a plurality of remote communication units (18). A communication resource controller (14) provides system sy |
| 4949335 |
A TDM quasi-duplex system |
August 14, 1990 |
| An improved quasi-duplex time division multiplexed (TDM) communication system provides for transmission by a talker until an interrupt command for role reversal is transmitted by a listener. Preferably, the time allocated for voice transmission is greater than the time allocated for |
| 4941203 |
Two-way radio communication system having selectable operating modes |
July 10, 1990 |
| A radio communication system includes a base station and a plurality of remote units. The remote units can be operated in one of several modes. In the Message Storage mode, a telephone or remote unit caller is verbally informed that the called remote unit is not receiving calls, and the |
| 4466001 |
Polling system for multiple terminal units |
August 14, 1984 |
| A semi-duplex communication system provides high channel efficiency by having the base station transmit a reference signal which each terminal uses as a sync signal. Each unit having data to send to the base responds with a very brief signal such as a burst of silent carrier transmission |
| 4398192 |
Battery-saving arrangement for pagers |
August 9, 1983 |
| A pager or other selectively-addressed electronic device powered by a small power cell operates in four different modes and at two power levels, depending on signals received and a timing sequence. The device can stay active continuously, be activated at intervals or remain in a powered- |
| 4251865 |
Polling system for a duplex communications link |
February 17, 1981 |
| Channel efficiency in a communications link between a controller and multiple portable units is increased by polling the active units and a set number of inactive units in a sequence where a "poll" consists of sending the binary coded address of the portable unit. The stream of transmitt |
| 4247908 |
Re-linked portable data terminal controller system |
January 27, 1981 |
| A two-way communications system for use with a host computer includes a control unit, a base station and multiple radio/data terminal units. The control unit interfaces directly with the computer but uses a radio link to the portable units. Voice and data signals can be transmitted and d |
