Transmittal of heartbeat signal at a lower lever than heartbeat request

• US 20070223426A1
• Filed: 05/22/2007
• Published: 09/27/2007
• Est. Priority Date: 06/01/1998
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Tantivy Communications Incorporated (InterDigital, Inc.)
• Inventors: Proctor, James
• Granted Patent: US 8,134,980 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04L 1/165 Variable formats
• CPC Class Codes: H04L 25/14 Channel dividing arrangements , i.e. in which a single bit stream is divided between several baseband channels and reassembled at the receiver
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 7/06 the synchronisation signals differing from the information signals in amplitude, polarity or frequency or length
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 2213/13098 Mobile subscriber
• CPC Class Codes: H04Q 2213/13202 Network termination [NT]
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13216 Code signals, frame structure
• CPC Class Codes: H04Q 2213/1327 Release and resetting of connection
• CPC Class Codes: H04Q 2213/13298 Local loop systems, access network
• CPC Class Codes: H04Q 2213/13332 Broadband, CATV, dynamic bandwidth allocation
• CPC Class Codes: H04Q 2213/1336 Synchronisation
• CPC Class Codes: H04Q 2213/13389 LAN, internet
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/26 Resource reservation
• 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 52/16 Deriving transmission power values from another channel
• CPC Class Codes: H04W 52/325 : Power control of control or pilot channels
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/04 : Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 74/0866 : using a dedicated channel for access
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/28 : Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 8/005 : Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/14 : WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 88/02 : Terminal devices

Abstract

A communication system, such as a wireless CDMA system, detects markers with fewer errors by having field units transmit the markers at different power levels (e.g., 9 dB for one marker and 11 dB for another marker). The difference in power levels of the markers allows the base station to identify the request markers using alternative criteria with a low probability of error, where the alternative criteria may include comparing the markers to respective energy level thresholds, monitoring occupancy of time slots, occupancy of mutually exclusive code channels, or combinations thereof. For example, in one particular embodiment, a request marker, which is generally a high priority marker, is transmitted with higher power, which improves the probability of detection and reduces the probability of false detection of the request marker.

Claims

1. A code division multiple access (CDMA) user device comprising:

an antenna; and

a controller configured to control a CDMA transceiver such that a connection with a network is established, a signal is transmitted from the CDMA user device to a base station over a reverse link to indicate the presence of the CDMA user device to the base station, at least one signal is transmitted from the CDMA user device to the base station over the reverse link requesting that the base station reserve at least one reverse link traffic channel.

2. The CDMA user device according to claim 1 wherein the CDMA transceiver is configured to transmit the signals at different power levels.

3. The CDMA user device according to claim 1 wherein the reverse link channel comprises a plurality of channels.

4. The CDMA user device according to claim 3 wherein the traffic channels are divided in time by radio frames that are further subdivided into subframes.

5. The CDMA user device according to claim 4 wherein the subframes include at least one time slot.

6. The CDMA user device according to claim 3 wherein each channel occupies a 1.25 MHz band.

7. The CDMA user device according to claim 1 wherein the signal indicating the presence of the CDMA user device to the base station is transmitted over a maintenance channel in the reverse link.

8. The CDMA user device according to claim 7 wherein the signal maintains timing between the CDMA user device and the base station.

9. The CDMA user device according to claim 7 wherein the signal maintains power control between the CDMA user device and the base station.

10. The CDMA user device according to claim 1 wherein the energy level of the at least one signal requesting at least one reverse link traffic channel is compared against a predetermined energy threshold before the base station allocates at least one reverse link traffic channel.

11. The CDMA user device according to claim 10 wherein each reverse link traffic channel supports variable data rates from 2.4 kbps to 160 kbps.

12. The CDMA user device according to claim 1 wherein the CDMA transceiver is configured to operate over a plurality of allocatable radio frequency channels.