Performance evaluation of UMTS packet voice call control

SIP-based session establishment over an integrated satellite-terrestrial 3G network

“…The round-trip delay over the UMTS IP Core Network was assumed to be 150 ms [19], while the mean one-way Internet delay and its standard deviation are 50 ms and 7 ms, respectively [20]. The processing time per SIP message in each server is 25 ms [6] while the RLC processing time was assumed to be 15 ms for both uplink and downlink communications [21]. The mobile satellite channel model used was a simplification of the Lutz statistical model [22], where the fading process is switched between a good state (unshadowed areas) and a bad state (shadowing areas).…”

“…The only work available in the open literature is by Eyers and Schulzrinne [4], which predicted the call setup delays over the public Internet, while Kamioka and Yamada [5] only looked at the call setup performance in the 3GPP-based IP networks from the viewpoint of the processing delay of the servers and the network delay of the IP network. Most recently, Foster et al [6] presented performance evaluation results for SIP call setup delays over the terrestrial UMTS air interface and proposed message compression techniques to reduce the delay over the radio access network. For the satellite case, on the other hand, previous work on call setup for an IP-based S-UMTS network has only been based on the ITU Q.931 protocol [7][8].…”

Performance analysis of session initiation protocol based call set-up over satellite-UMTS network

“…Although a second set of results was also presented in [7] for lossy channels with limited bandwidth, the measurement was not performed over a 3G network configuration, but instead a general-purpose IP network emulator was used. In [8], it has been found that UMTS SIP call set-up delays are excessive compared to GSM and UMTS circuit-switched call control and therein, a textbased message compression technique has been proposed; nevertheless, the impact of the wireless link errors was again not taken into account in their evaluation.…”

Enhancing the radio link protocol for VoIP session establishment signalling over satellite-UMTS

“…The roundtrip delay over the UMTS 1P Core Network was assumed to be 150 ms [ 7 ] , while the mean one-way Internet delay and its standard deviation are 50 ms and 7 ms, respectively [ 8 ] . The processing time per SIP message in each server is 25 ms [ 2 ] while the RLC processing time was assumed to be 15 ms for both uplink and downlink communications [9]. It was assumed that there is no loss in the fixed network, while for the air interface, an erroneous link with parameterized block error rate (BLER) was considered, whereby the errors were assumed to he uniformly distributed (uncorrelated).…”

“…This is made worse when transversing an error-prone wireless link with a larger satellite propagation delay. One of the techniques to reduce the session setup delay is by compression of the signalling messages, such as the text-based message compression technique proposed in [2]. Our approach to improve the session setup performance is by incorporating a link layer retransmission based on the Radio Link Control acknowledgement mode (RLC-AM) [3] mechanisms as a method to conceal link-related losses from the upper layers.…”