Optimal rate adaptation for VoIP over wireless tandem links

Current Challenges and Opportunities in VoIP over Wireless Networks

“…Another limitation briefly discussed in this book chapter is the relatively limited CPU power capabilities of the mobile devices and terminals, so the deployed algorithms and applications should take that into account. Furthermore, we have discussed some of the proposed solutions in the literature that can greatly improve the performance of wireless VoIP, namely we discussed two main approaches; the first one is called the Hybrid Media-Error-Correction scheme [15] and the second one is the Optimal Rate Adaptation scheme [20]. Finally, we discussed a proposed extension to the current Call Admission Control schemes used in the wireless domain.…”

“…So it is a trade-off between voice quality and error correcting capabilities. This problem was tackled and a proposed solution was suggested in [20]. In what follows, we briefly describe the proposed solution but we highly encourage the reader to refer to the paper for more details.…”

“…So it is a trade-off between the voice encoding quality and the error correcting capabilities of each frame. shows how each voice frame is aligned vertically, such that packets are formed horizontally such that each packet contains one symbol from each voice frame [20] Now once the optimal source and channel encoding rates are determined for each voice frame, the symbols are aligned into a two-dimensional grid of symbols as shown on figure 12 (b), where the encoded voice frames with their channel coding symbols are aligned vertically, and packets are formulated horizontally, i.e. the packet is formulated by taking one symbol from each voice frame.…”

“…13. Performance evaluation of ORA algorithm, using the dg129 speech clip [23] to simulate a VoIP call, utilizing 1x1 MIMO link configuration, with a transmission budget of BT = 5,6 Kbytes, and a 10% average packet erasure rate [20] We conclude this subsection by showing the performance evaluation results of the optimal rate adaptation scheme under tandem wireless channel that is prone to bit errors and packet erasure. The same experiment setup used in the previous subsection is used here.…”

A dynamic rate adaptation algorithm using WB E-model for voice traffic over LTE network

“…There are several authors who have proposed techniques to improve the speech quality delivered over a noisy channel. Examples include the works of [3], [4], [5], [6], [7], and [8]. But the closest works related to our paper are represented in [3], [7], and [8].…”