US 6,925,068 B1 · Method and apparatus for allocating bandwidth in a wireless communication system

Abstract

An adaptive time division duplexing (ATDD) method and apparatus for duplexing transmissions on a communication link in wireless communication systems. Communication link efficiency is enhanced by dynamically adapting to the uplink and downlink bandwidth requirements of the communication channels. Time slots are flexibly and dynamically allocated for uplink or downlink transmissions depending upon the bandwidth needs of a channel. Communication link bandwidth requirements are continuously monitored using sets of pre-determined bandwidth requirement parameters. Communication channels are configured to have either symmetric or asymmetric uplink/downlink bandwidths depending upon the needs of the channel. Channel bandwidth asymmetry can be configured alternatively in favor of the uplink transmissions.(i.e., more time slots are allocated for uplink transmissions than for downlink transmissions) or in favor of the downlink transmissions (i.e., more time slots are allocated for downlink transmissions than for uplink transmissions). A myriad of time slot allocation schemes are possible. One simplified time slot allocation scheme uses a “frame-based” approach. A preferred channel bandwidth analysis technique is disclosed which monitors and updates bandwidth requirement parameters associated with communication sessions, base stations and cell cluster controllers. In accordance with this technique, a communication session is preferably assigned both an “initial” and an “actual” set of bandwidth parameters.

Claims36

Dependent claims

A method for adaptively duplexing transmissions in a communication link using a time division duplexing scheme wherein transmissions are communicated in an uplink direction during uplink time slots and wherein transmissions are communicated in a downlink direction during downlink time slots, comprising the steps of:

(a) monitoring bandwidth usage in the communication link over a period of time to determine uplink and downlink bandwidth utilization parameters;
(b) predicting an uplink bandwidth requirement and a downlink bandwidth requirement of the communication link, wherein the uplink and downlink bandwidth requirements are predicted using the uplink and downlink bandwidth utilization parameters;
(c) setting an uplink/downlink bandwidth requirement ratio based upon the uplink and downlink bandwidth requirements of the link;
(d) allocating uplink and downlink time slots in a frame with the set uplink/downlink ratio in response to bandwidth requests;
and
(e) enabling uplink transmissions during the allocated uplink time slots and downlink transmissions during the allocated downlink time slots.

3 more elements

A method for monitoring and updating uplink and downlink bandwidth requirements for a communication link using a time division duplexing scheme wherein transmissions are communicated in an uplink direction during uplink time slots and wherein transmissions are communicated in a downlink direction during downlink time slots, comprising:

(a) determining an initial set of bandwidth utilization parameters, wherein the initial bandwidth utilization parameters comprise an estimate of the uplink and downlink bandwidth requirements;
and
(b) updating the initial set of bandwidth utilization parameters with an actual set of bandwidth utilization parameters reflective of an actual bandwidth utilization of the uplink and downlink time slots, wherein the actual set of bandwidth parameters are calculated as follows:
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and wherein U(M)n, D(M)n comprise uplink and downlink filtered moments, respectively, of order M at an instant n, and wherein Un, Dn respectively comprise an uplink and downlink accumulated bandwidth requirement influenced by the actual bandwidth utilization.

144 more elements

Dependencies are inferred from the claim text.

Method and apparatus for allocating bandwidth in a wireless communication system

Life of this patent

Method and apparatus for allocating bandwidth in a wireless communication system

Life of this patent

Abstract

Claims36