Uplink Buffer Status Reporting for Delay Constrained Flows in 3GPP Long Term Evolution

Scheduling of uplink data by the network typically requires that the buffer status information from each User Equipment (UE) is available at the network to ensure that the air interface resources are not wasted. The presence of delay constrained flows or radio bearers at the UE may impose a constraint that the delay information be available at the network in addition to the size of buffer data. In this paper, we discuss the different uplink buffer status reporting schemes considered in 3GPP Long Term Evolution (LTE) and the current agreement. We propose modified limited feedback buffer status reporting schemes for delay-constrained radio bearers. Using simulation results, we illustrate that delay information at the network is important for scheduling real-time flows without dropping packets.