Binding adaptation method in cell systems optimized to differentiate between high and low variability

摘要

"METHOD OF ADAPTATION OF CONNECTION IN OPTIMIZED CELL SYSTEMS TO DIFFERENTIATE BETWEEN HIGH AND LOW VARIABILITY". The invention relates to a method for effecting link adaptation on the radio interfaces of an optimized packet cellular data network that handles various Modulation and Coding Schemes (MCS) to maximize data production. At a preliminary off-line stage, the system behavior in terms of net production of the various available MCSs is simulated for different C / I conditions. From the simulation, two sets of tables are obtained, each including rising and falling limits expressed in terms of Block Error Rate (BLER). Limits correspond to switching points from one MCS to the two available MCSs that have the lowest or highest immediate protection. Both sets of tables refer to more or less diverse RF environments, and further specialize to take into account EGPRS type II hybrid ARQ, namely Incremental Redundancy (IR). During transmission, the transmitted blocks are checked for FEC, and the results are sent to the network. The network continually updates BLER using exponential leveling. In order to obtain the correct time response, regardless of whether RLC blocks are received or not, a reliability filter is provided whose output is used to decide the weight between new and old measurements to take the filter pulse response. of exponentially decreasing BLER over time. IR efficiency is tested for each incoming block, and an indicative IR_status variable is filtered using the same approach adopted for BLER. Each actual BLER limit to be used in binding adaptation is obtained by a linear interpolation between the table bound without IR and with perfect IR, both weighted with filtered IR_status. The filtered BLER is then compared against said interpolated thresholds to test for the arrival of an MCS switching condition. Power control aims to keep peak QoS production per time interval constant (Figure 16).