摘要:
A variable length sequence number is used to identify data units in a communication channel. The sequence number associated with the most recent data that has been received successfully and the sequence number expected with the next new data message to be received are examined to determine the minimum size sequence number necessary to unambiguously identify to the transmitter incorrectly received data that must be retransmitted in a later message. The receiver provides the transmitter with the sequence number associated with the last successfully received byte of data and the sequence number associated with the next expected byte of data. The receiver communicates this information to the transmitter using a NAK control message. The transmitter then uses the sequence number of the next byte of data to be transmitted and the information received in the control message from the receiver to determine the smallest number of bits necessary to represent the sequence numbers for both data transmissions and the retransmission of data that was not received properly by the receiver.
摘要:
A back haul architecture enables efficient primary transfer (i.e., transfer of the designation of primary base station from one base station to another). A frame selection/distribution (FSD) function queues packets of forward-link data—to which sequence numbers have been assigned—for packet-mode transmission over the back haul only to one base station—the current primary base station—where the packets are again queued for over-the-air transmission to the mobile unit. If and when it becomes appropriate to transfer the designation of primary base station to another base station, there may still be packets of data queued at the old primary base station awaiting transmission to the mobile unit. The old primary base station sends a message to the new primary base station indicating a particular sequence number that identifies the remaining packets of forward-link data queued at the old primary base station. The new primary base station then sends a message to the FSD function requesting transmission of those packets of forward-link data corresponding to the particular sequence number. The FSD function then transmits those requested packets of forward-link data to the new primary base station, which queues the requested packets for over-the-air transmission to the mobile unit. In this way, transmission of all of the forward-link data to the mobile unit is enabled without having to transmit the remaining queued packets of forward-link data from the old primary base station to the new primary base station over the back haul, thereby providing an efficient mechanism for primary transfer in wireless communications systems that support forward-link data transmissions only in simplex mode.
摘要:
Bursts of additional bandwidth (e.g., one or more supplemental channels or a channel having variable bandwidth) is assigned to users (e.g., high-speed data users) in a cellular telecommunication system. A request for assignment of additional bandwidth may be an initial request, a continuation request for an on-going burst, or a retry request after a previously rejected request. In any case it is determined whether to grant or reject the request. If the request is rejected, instructions are given to submit a retry request after a specified backoff time. The present invention may be implemented using either an asynchronous approach or a synchronous approach. According to the asynchronous approach, all requests are handled asynchronously. According to the synchronous approach, initial requests are handled asynchronously, but continuation requests and retry requests are handled synchronously at epoch times that coincide with specific time slots.
摘要:
A code division multiple access system method and apparatus provides for allocation of increased bandwidth to a requesting mobile station. An access controller receives a data burst request (from either a requesting mobile station or from an external network already in connection with the mobile station) requesting a first data rate in excess of the basic data rate B allocated to a mobile station of a first cell. The access controller determines an increased data rate which is to be granted to said mobile station without causing excessive interference at said first cell and at least one adjacent cell and transmits a data burst assignment to a base station of said first cell indicating the increased data rate which has been granted to said mobile station. In another feature, the access controller processes a data burst request received from a mobile station involved in a soft handoff between multiple base stations and negotiates with those base stations for an increased data rate which may be granted to the requesting mobile station. One feature enables additional interactions to further refine the allocation process. A variety of system architectures are also described.
摘要:
In the method of processing soft handoff information at a base station, soft handoff information of a mobile station is received at the base station. The soft handoff information indicates at least a number of base stations in an active list of the mobile station. The active list is a list of base stations involved in a call of the mobile station. The base station applies a rules set to the soft handoff information to determine changes in the active list. The rules set requires more stringent conditions be met to add a base station to the active list when the active list includes a first number of base stations as compared to when the active list includes a second number of base stations; wherein the first number is greater than the second number. The determination results are then sent to the mobile station.
摘要:
A technique for controlling the power with which a wireless terminal transmits is disclosed. One embodiment of the present invention comprises: transmitting a first signal at a first power level; receiving a series of n power control signals, bi−n+1 through bi; setting a step size based on a measure of dispersion of the n power control signals; and transmitting a second signal at a second power level that is based on the first power level and the step size.
摘要:
In a wireless communication system, in which a mobile station is operable to monitor the signal strengths of a plurality of pilot signals transmitted from a plurality of base stations, a method and device by which the mobile station determines the membership of Active Set pilots by generating a quality metric derived as a function of (i) detected pilot signal strengths corresponding to the Active Set of pilots, and (ii) detected pilot signal strengths corresponding to a non-Active Set of pilots, determining a threshold value, the threshold value determined as a function of the quality metric, and assigning the pilot to, or removing the pilot from, the Active Set of pilots if the signal strength corresponding to the pilot exceeds the threshold value.
摘要:
A back haul architecture effectively reduces the reactivation times for both forward-link and reverse-link data transmissions over CDMA wireless communications systems, by relying on packet-mode transmissions over the back haul between a frame selection/distribution (FSD) function and the appropriate base stations. In particular, for the forward direction, the FSD function transmits forward-link data only to one base station, which is solely responsible for controlling the forward-link air interface with the corresponding mobile unit. For the reverse direction, each base station that receives frames of reverse-link data from the mobile unit, assigns a time tag to the frame, divides the frame into one or more data packets, assigns a different sequence number to each data packet, and transmits the data packets to the FSD function over the back haul, all without first synchronizing time with any other base station that is also operating in reverse-link soft hand-off with that mobile unit.
摘要:
A code division multiple access system provides a way of allocating an increased data rate to a requesting mobile station. A mobile station requesting a data rate in excess of the basic data rate sends received pilot strength data for its base station and base stations in adjacent cells. The received pilot strength data is used to determine an increased data rate to be assigned to the requesting mobile station. One feature assigns an increased data rate based on the difference in the maximum received received pilot strength data from a non-active base station (one not in connection with the mobile station) and the maximum received pilot strength data from an active base station (one in connection with the mobile station). Yet another feature utilizes a series of threshold levels, each pair of levels associated with a different permitted data rate. Using the received pilot strength data, a data rate is determined which satisfies all adjacent cell interference concerns. Another feature uses average adjacent cell capacity loads rather than threshold levels, together with the received pilot strength data, to determine the appropriate increased data rate to be assigned to a user requesting an increased data rate.
摘要:
A method for increasing the success rate for soft handoffs, particularly under rapidly fluctuating fading conditions, using traffic channels of active set base stations. In one embodiment of the present invention, increased success rate for soft handoffs is achieved using a candidate base station, in addition to the active set base stations, to transmit a handoff command message to the mobile-telephone. Specifically, the handoff command message is transmitted by the active set base stations over the traffic channels assigned to mobile-telephone for communicating with the active set base stations, and by the candidate base station over the traffic channel assigned to the mobile-telephone for communicating with a primary base station. Additionally, a pilot signal may be transmitted by the candidate base station to enable the mobile-telephone to coherently demodulate the handoff direction message transmitted by the candidate base station.