Browse Prior Art Database

Capacity Aware, Speculative F-SCH Channel Assignment

IP.com Disclosure Number: IPCOM000007984D
Original Publication Date: 2002-May-09
Included in the Prior Art Database: 2002-May-09

Publishing Venue

Motorola

Related People

Authors:
John M. Harris Ivan N. Vukovic

Abstract

Our current SCH assignment algorithm is not aggressive enough nor speculative enough when the system is lightly loaded. WAP Downloads, in general, do not get any benefit from the SCH in CDMA given current CDMA Scheduling Algorithm. Currently, in the infrastructure, the PCF/SDU generates a F-SCH request only after a threshold amount of data is in the PCF/SDU queue waiting to be sent to a user. SCH assignments are typically made for a duration of some msecs. The proposal is to send Speculative assignment requests (SAR) from SDU to TSM (Time Slice Manager at BTS). TSM only schedules speculative slices when extra resources remain after all real assignment requests for that slice have been satisfied, and when that slice is about to expire. A Time Slice expires if it is not assigned by BTS_TS LeadTime in advance. Time slice assignment requires a scheduling horizon. If it is not assigned before then, it goes to waste. It is these otherwise wasted slices that will be used by the speculative requests. Speculative requests will be based on opposite direction activity, dormant to active transition, and recent same direction traffic. A mechanism for controlling the degree of speculation is also planned. If 90% of speculative request have been denied, then SDU will be less speculative. If all of the speculative requests have been accepted, then SDU will be more speculative (up to a maximum amount of speculative-ness). This reduces the backhaul capacity hit due to overly-speculative (e.g. point less) requests. Results in roughly a 1 second decrease in the download time.