Empirical Evaluation of VoIP Aggregation over a Fixed WiMAX Testbed

Abstract

The WiMAX Reference Network Architecture can be used in point-to-point and point-to-multipoint network topologies, and is suitable for providing last-mile, building-to-building, and residential broadband connectivity. Another major application, and the main focus of this study, is the use of fixed WiMAX as backhaul for voice and data services. We evaluate voice over IP (VoIP) performance over a fixed WiMAX testbed and quantify the benefits from employing applicationand network-level aggregation. We examine such aggregation schemes using our fixed WiMAX testbed and report the results for both uplink and downlink. If we use objective mean opinion scores (MOS) as the main gauge of overall performance, application-layer aggregation appears to be the best scheme, allowing our fixed WiMAX testbed to sustain nearly three times more flows in the downlink and over two times more flows in the uplink than when no aggregation is used, at comparable MOS values.

A Packet Aggregation Mechanism For Real Time Applications Over Wireless Networks

“…However, the frame aggregation operations are too complex and the adaptation method increases the load operations in the access point manager. Pentikousis et al [13] present a frame aggregation method for a fixed WiMAX testbed, where single hop communications are considered. Pinola et al [17] investigated the impact of the OFDMA and OFDM modulation techniques when frame aggregation is used over a WiMAX environment.…”

“…The proposals in [3], [5], [9], [10], [11], [16], [18], [23] work at the network layer. Proposals in [13], [17], [24], [26], on the other hand, work at the data link layer. The network layer aggregation proposals can be also classified as multi-hop ( [3], [5], [9], [10], [11], [16], [18]) or single-hop ( [23]).…”

Analysis of deficit round robin scheduling for future aeronautical data link

“…The AMBE-ATC-10B vocoder produces a voice frame with 96 bit length every 20 ms, which corresponds to a data rate of 4.8 kbit s −1 . According to the L-DACS 1 specification, three voice frames are aggregated and transmitted together so that the overhead due to lower layers is reduced and the capacity of the wireless link is better utilized [19]. Fig.…”

WiMAX backhaul for environmental monitoring

“…1 illustrates the experimental facility used in our empirical performance evaluation study. At the center of it lies an Airspan MicroMAX-SoC fixed WiMAX BS and an Airspan ProST SS (see Table 1 for configuration parameters and [6,7]). Symmetrically on the BS and SS side, we connect GNU/Linux (kernel ver.…”

“…We revisit the communication/computation tradeoff and quantify the gains from application-and network level data aggregation discussed in [4,7]. We focus on measuring performance only on the uplink (UL) as we anticipate that several SSs could transmit environmental data to a single base station (BS), possibly employing directional antennas.…”