초록 ▼

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 t

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.

대표청구항 ▼

1. A field unit comprising: at least one processor configured to transmit a first signal having one of a plurality of formats; wherein each of the plurality of formats has a power offset associated with that format; wherein at least two of the formats have a different power offset; wherein the first

1. A field unit comprising: at least one processor configured to transmit a first signal having one of a plurality of formats; wherein each of the plurality of formats has a power offset associated with that format; wherein at least two of the formats have a different power offset; wherein the first signal is transmitted in response to the field unit not having an allocation of traffic data resources;on a condition that the field unit requires an allocation of traffic data resources, the at least one processor configured to transmit the first signal with a format of the plurality of formats associated with a request; wherein at least one of the formats is not associated with the request;in response to the request, the at least one processor configured to receive an allocation of traffic data resources and transmit reverse link data in response to the allocation in a time interval including at least one time slot; andthe at least one processor configured to receive power commands and adjust the transmission power level of the first signal in response to the power commands. 2. The field unit of claim 1 wherein the power offsets are in fixed dB values. 3. The field unit of claim 1 wherein the first signal with the format associated with the request is derived from at least an orthogonal code. 4. The field unit of claim 1 wherein the first signal with the format associated with the request does not have a modulated bit. 5. The field unit of claim 1 wherein the at least one processor is only configured to transmit the first signal on a condition that the reverse link timing is maintained with a wireless network. 6. A field unit comprising: at least one processor configured to maintain a connection with a network during packet transfer by: in response to having data to transmit and having no assigned reverse link resources, transmitting a request for resources in a time interval including at least one slot, andin response to not having data to transmit and having no assigned resources, to not transmit the request in the time interval;in response to transmitting the request for resources, the at least one processor configured to receive an assignment of reverse link resources and to transmit reverse link data in response to the assignment of reverse link resources in a second time interval including at least one time slot; andin response to received power commands, the at least one processor configured to adjust a transmission power level of the request or the reverse link data in accordance with the power commands. 7. The field unit of claim 6 wherein the request is transmitted as a signal not including a modulated bit. 8. The field unit of claim 6 wherein the at least one processor is further configured to transmit in a third time interval other than the first and second time interval, a signal having a power level offset from a transmission power level of the request. 9. The field unit of claim 6 wherein the power offset is a fixed dB value. 10. The field unit of claim 6 wherein the request is transmitted as a signal derived from an orthogonal code. 11. The field unit of claim 6 wherein the at least one processor is only configured to transmit the request on a condition that the reverse link timing is maintained with a wireless network. 12. A base station comprising: at least one processor configured to maintain connections with subscriber units transmitting packet data by receiving transmissions from the subscriber unit in time intervals when the subscriber units are not transmitting packet data; wherein each time interval includes at least one time slot; wherein the received transmissions are in a plurality of formats and at least one of the formats includes an indication that a subscriber unit desires to transmit packet data; andthe at least one processor configured to determine whether a subscriber unit is requesting to transmit data by detecting an energy level associated with the time interval. 13. The base station of claim 12 wherein the processor is further configured to transmit power commands to the subscriber units to adjust power levels of the transmissions in the time intervals when the subscriber units are not transmitting packet data. 14. The base station of claim 12 wherein the received transmissions are derived from at least one orthogonal code. 15. The base station of claim 12 wherein the format indicating that the subscriber unit desires to transmit packet data does not have a modulated bit.