Understanding LTE Model Internals and Interfaces
Understanding LTE Model Internals and Interfaces
Understanding LTE Model Internals and Interfaces
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1581 <strong>Underst<strong>and</strong>ing</strong> <strong>LTE</strong> <strong>Model</strong> <strong>Internals</strong> <strong>and</strong> <strong>Interfaces</strong>Scheduler Support at the eNodeB• Frame generator, <strong>and</strong> the scheduler are distinct entities• Frame generator deals with the “framing” <strong>and</strong> underst<strong>and</strong>s the resources available for data, howbits can be mapped to these resources etc• Scheduler is oblivious to the “frame”• Ideally, you should be able to use the scheduler package for any entity• Scheduler only finds the identity <strong>and</strong> optionally the number of bits of the “next queue to serve”• By default, the scheduler is even oblivious to RLC (data buffers), although this need not be thecase• Scheduler can recommend “infinity”, <strong>and</strong> the frame generator will decide exactly howmany bits are served• If the scheduler does specify a finite number, the frame generator treats it as the “upperlimit” of the amount of bits to be served• Frame generator is a client of the scheduler• Very complex…needs to manage multiple RBs per UE, decide termination criterion etc• Can block/unblock some scheduler queues to exclude/include them in scheduling• Scheduler code:• Scheduler code is implemented in lte_sched_support.ex.c <strong>and</strong> lte_sched_sup.h• Frame generator code is in lte_enb_as.pr.m:• DL function: lte_enb_as_dl_frame_generate()• UL function: lte_enb_as_ul_frame_generate()CONFIDENTIAL ─ RESTRICTED ACCESS: This information may not be disclosed, copied, or transmitted in any format without the prior written consent of OPNET Technologies, Inc. © 2010 OPNET Technologies, Inc.44