Trunked radio repeater system with control channel monitoring feature

• US 5,483,670 A
• Filed: 08/12/1993
• Issued: 01/09/1996
• Est. Priority Date: 06/03/1987
• Status: Expired due to Term

• Current Assignee: Pine Valley Investments, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Ericsson GE Mobile Communications Inc (Telefonaktiebolaget LM Ericsson)
• Inventors: Dissosway, Marc A., Cooper, Gerald M., Hughes, Houston H. III, Childress, Jeffrey S.
• Primary Examiner(s): Urban, Edward F.
• Application Number:
  US08/105,153
• Time in Patent Office: 880 Days
• Field of Search: 455/33.1, 455/34.1, 455/34.2, 455/54.1, 455/54.2, 455/56.1, 455/166.1, 455/166.2, 379/58, 379/60, 379/63
• US Class Current: 455/515
• CPC Class Codes: H04L 1/14 in which the signals are sent back to the transmitter to be checked ; echo systems
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 25/06 Dc level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection
• CPC Class Codes: H04W 84/08 Trunked mobile radio systems

Abstract

A digitally trunked radio repeater system provides substantial improvements in timeliness of channel acquisition and channel drop, and in reliability of critical control signalling. The system uses a much higher digital signalling rate than is typically found in prior art systems, and uses a control channel to convey digital channel request and assignment messages between the central site and mobile transceivers. The mobile radio transceivers transmit channel requests on the control channel (if no response is received, the mobile retries during a retry time window which increases in duration in dependence on the number of retries). The mobile transceiver switches to a working channel in response to an assignment message received on the control channel. Subaudible digital signals transmitted on the control channel and on active working channels allow late entry, shifting to higher priority calls, and other advanced functions. Message and transmission trunking capabilities are both present so as to maximize working channel usage without compromising channel access for high priority communications. During transmission trunking, called and calling receivers return to the control channel after each transmission (and called transceivers may be inhibited from transmitting) but grant higher priority to calls from the other transceivers being communicated with by temporarily disabling the monitoring of the control channel with respect to the remaining other predetermined call groups to ensure continuity over an entire conversation.

Claims

1. A method for achieving reliable and prompt communication within a trunked radio repeater system having a digital control channel and plural working channels, which working channels are assigned for temporary use by individual radio units specified by digital control signals on the control channel, said method comprising the steps of:

in a non-called quiescent state, monitoring by an individual radio unit the control channel for channel assignments to each of multiple predetermined call groups of differing predetermined priorities including a first predetermined priority call group to which the individual radio unit is assigned and conducting a communique on an assigned working channel with other radio units of the first predetermined priority call group in response to detection of such channel assignment;

continuously monitoring the assigned working channel during said communique for further sub-audibile channel assignments to others of said plural predetermined call groups; and

upon termination of the communique involving the first predetermined priority call group, monitoring the control channel while temporarily disabling the monitoring of the control channel with respect to the multiple predetermined call groups other than the first predetermined priority call group for a predetermined time period.

2. A method for achieving reliable and prompt communication within a trunked radio repeater system having a digital control channel and plural working channels, which working channels are assigned for temporary use by individual radio units specified by digital control signals on the control channel, said method comprising the steps of:

in a non-called quiescent state, monitoring by an individual radio unit the control channel for channel assignments to each of plural predetermined call groups to which the individual radio unit is assigned and conducting a communique on the working channel with other radio units of a first predetermined non-priority call group in response to detection of such channel assignment;

continuously monitoring the assigned working channel during said communique for further sub-audible channel assignments to others of said plural predetermined call groups; and

upon termination of the communique involving the predetermined non-priority call group, monitoring the control channel while temporarily ignoring a further channel assignment with respect to non-priority call groups other than said first predetermined non-priority call group for a predetermined time period.

3. Apparatus for achieving reliable and prompt communication within a trunked radio repeater system having a digital control channel and plural working channels, which working channels are assigned for temporary use by individual radio units specified by digital control signals on the control channel, said apparatus comprising:

a radio unit for monitoring the control channel, in a non-called quiescent state, for channel assignments to each of plural predetermined call groups of differing predetermined priorities including a first predetermined priority call group and for conducting a communique on an assigned working channel with other radio units of the first predetermined priority call group in response to detection of such channel assignment;

said radio unit monitoring the assigned working channel during said communique for further channel assignments to others of said plural predetermined call groups;

monitoring the control channel while and

means for temporarily disabling the monitoring of the control channel with respect to the predetermined call groups other than the first predetermined priority call group for a predetermined time period upon termination of a communique involving the first predetermined priority call group.

4. Apparatus for achieving reliable and prompt communication within a trunked radio repeater system having a digital control channel and plural working channels, which working channels are assigned for temporary use by individual radio units specified by digital control signals on the control channel, said apparatus comprising:

a radio unit for monitoring the control channel, in a non-called quiescent state for channel assignments to each of plural predetermined call groups and for conducting a communique on an assigned working channel with other radio units of a first predetermined non-priority call group in response to detection of such channel assignment;

said radio unit monitoring the assigned working channel during said communique for further channel assignments to others of said plural predetermined call groups; and

means for further monitoring the control channel while temporarily ignoring a further channel assignment with respect to non-priority call groups other than said first predetermined non-priority call group for a predetermined time period upon termination of the communique.

5. A method for achieving reliable enablement of only a predetermined subset of programmed radio device features within any one of plural such radio devices which are to be used for two-way trunked communication within a trunked radio repeater system via a central control site while nevertheless yet permitting program feature enablements to be effected by an end user of each radio device, said method comprising the steps of:

programming all said radio devices so as to each be capable of performing a full set of available feature functions provided that a given such feature is enabled by the appropriate setting of a predetermined corresponding feature enable data field;

providing with each radio device, a set of program codes as an encryption of (a) the feature enable data field(s) authorized to be set and (b) a physical identification code unique to said each radio device;

providing a device programmer which (a) accepts said encrypted program codes and, in response, automatically sets said feature enable data fields and physical identification fields within any of said radio devices and (b) sets a just-programmed data field within said radio device; and

if said just-programmed data field is set, requesting assignment of a new logical identification for the device from the central control site based on the apparent physical identification when the radio device is next enabled.