The Community for Technology Leaders
RSS Icon
Issue No.01 - January (2009 vol.8)
pp: 93-108
Hung-Yun Hsieh , National Taiwan University, Taipei
Chung-Wei Li , National Taiwan University, Taipei
Hsiao-Pu Lin , National Taiwan University, Taipei
In this paper we investigate the problem of voice communications across heterogeneous telephony systems on dual-mode (WiFi and GSM) mobile devices. Since GSM is a circuit-switched telephony system, existing solutions that are based on packet-switched network protocols cannot be used. We show in this paper that an enabling technology for seamless voice communications across circuit-switched and packet-switched telephony systems is the support of digital signal processing (DSP) techniques during handoffs. To substantiate our argument, we start with a framework based on the Session Initiation Protocol (SIP) for vertical handoffs on dual-mode mobile devices. We then identify the key obstacle in achieving seamless handoffs across circuit-switched and packet-switched systems, and explain why DSP support is necessary in this context. We propose a solution that incorporates time alignment and time scaling algorithms during handoffs for supporting seamless voice communications across heterogeneous telephony systems. We conduct testbed experiments using a GSM-WiFi dual-mode notebook and evaluate the quality of speech when the call is migrated from WiFi to GSM networks. Evaluation results show that such a cross-disciplinary solution involving signal processing and networking can effectively support seamless voice communications across heterogeneous telephony systems.
Network Protocols, Telephony, Wireless, Mobile Computing
Hung-Yun Hsieh, Chung-Wei Li, Hsiao-Pu Lin, "Handoff with DSP Support: Enabling Seamless Voice Communications across Heterogeneous Telephony Systems on Dual-Mode Mobile Devices", IEEE Transactions on Mobile Computing, vol.8, no. 1, pp. 93-108, January 2009, doi:10.1109/TMC.2008.87
[1] Apple Inc., iPhone,, 2007.
[2] HTC Corp., CHT9100, http:/, 2006.
[3] HTC Corp., Dopod 818 Pro, http:/, 2006.
[4] M. Stemm and R. Katz, “Vertical Handoffs in Wireless Overlay Networks,” ACM/Kluwer Mobile Networks and Applications, vol. 3, no. 4, pp. 335-350, 1998.
[5] H.-Y. Hsieh, K.-H. Kim, Y. Zhu, and R. Sivakumar, “A Receiver-Centric Transport Protocol for Mobile Hosts with Heterogeneous Wireless Interfaces,” Proc. ACM MobiCom '03, pp. 1-15, Sept. 2003.
[6] R. Inayat, R. Aibara, and K. Nishimura, “A Seamless Handoff for Dual-Interfaced Mobile Devices in Hybrid Wireless Access Networks,” Proc. IEEE Int'l Conf. Advanced Information Networking and Applications (AINA '04), pp. 373-378, Mar. 2004.
[7] H.-H. Choi, O. Song, and D.-H. Cho, “A Seamless Handoff Scheme for UMTS-WLAN Interworking,” Proc. IEEE Global Telecomm. Conf. (Globecom '04), pp. 1559-1564, Nov. 2004.
[8] Generic Access to the A/Gb Interface; Stage 2, Third Generation Partnership Project, 3GPP TS 43.318 V6.7.0, July 2006.
[9] M. Buddhikot, G. Chandranmenon, S. Han, Y.-W. Lee, S. Miller, and L. Salgarelli, “Design and Implementation of a WLAN/CDMA2000 Interworking Architecture,” IEEE Comm. Magazine, vol. 41, no. 11, pp. 90-100, Nov. 2003.
[10] A. Salkintzis, G. Dimitriadis, D. Skyrianoglou, N. Passas, and N. Pavlidou, “Seamless Continuity of Real-Time Video across UMTS and WLAN Networks: Challenges and Performance Evaluation,” IEEE Wireless Comm. Magazine, vol. 12, no. 3, pp.8-18, June 2005.
[11] J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, and E. Schooler, SIP: Session Initiation Protocol, IETF RFC 3261, June 2002.
[12] A. Vemuri and J. Peterson, Session Initiation Protocol for Telephones (SIP-T): Context and Architectures, IETF RFC 3372, Sept. 2002.
[13] H. Schulzrinne and E. Wedlund, “Application-Layer Mobility Using SIP,” ACM Mobile Computing and Comm. Rev., vol. 4, no. 3, pp. 47-57, July 2000.
[14] R. Sparks, The Session Initiation Protocol (SIP) Refer Method, IETF RFC 3515, Apr. 2003.
[15] C. Elliott, “Stream Synchronization for Voice over IP Conf. Bridges,” master of engineering thesis, McGill Univ., Nov. 2004.
[16] S. Quackenbush, T. Barnwell III, and M. Clements, Objective Measures of Speech Quality. Prentice Hall, 1988.
[17] R. Steinmetz, “Human Perception of Jitter and Media Synchronization,” IEEE J. Selected Areas in Comm., vol. 14, no. 1, pp. 61-72, Jan. 1996.
[18] S. Weinstein, “Echo Cancellation in the Telephone Network,” IEEE Comm. Magazine, vol. 15, no. 1, pp. 8-15, Jan. 1977.
[19] A. Rix, M. Hollier, A. Hekstra, and J. Beerends, “Perceptual Evaluation of Speech Quality (PESQ): The New ITU Standard for End-to-End Speech Quality Assessment; Part I—Time-Delay Compensation,” J. Audio Eng. Soc., vol. 50, no. 10, pp. 755-764, Oct. 2002.
[20] L. Rabiner and B.-H. Juang, Fundamentals of Speech Recognition. Prentice Hall, 1993.
[21] S. Voran, “Perception of Temporal Discontinuity Impairments in Coded Speech—A Proposal for Objective Estimators and Some Subjective Test Results,” Proc. Int'l Conf. Measurement of Speech and Audio Quality in Networks (MESAQIN '03), May 2003.
[22] D.-S. Kim, “ANIQUE: An Auditory Model for Single-Ended Speech Quality Estimation,” IEEE Trans. Speech and Audio Processing, vol. 13, no. 5, pp. 821-831, Sept. 2005.
[23] Y. Liang, N. Farber, and B. Girod, “Adaptive Playout Scheduling and Loss Concealment for Voice Communication over IP Networks,” IEEE Trans. Multimedia, vol. 5, no. 4, pp. 532-543, Dec. 2003.
[24] H. Ilk and S. Guler, “Adaptive Time Scale Modification of Speech for Graceful Degrading Voice Quality in Congested Networks for VoIP Applications,” Signal Processing J., vol. 86, no. 1, pp. 127-139, Jan. 2006.
[25] R. Roucos and A. Wilgus, “High Quality Time Scale Modification for Speech,” Proc. IEEE Int'l Conf. Acoustics, Speech, and Signal Processing (ICASSP '85), Apr. 1985.
[26] D. Bigorgne et al., “Multilingual PSOLA Text-to-Speech System,” Proc. IEEE Int'l Conf. Acoustics, Speech, and Signal Processing (ICASSP '93), Apr. 1993.
[27] W. Verhelst and M. Roelands, “An Overlap-Add Technique Based on Waveform Similarity (WSOLA) for High Quality Time-Scale Modification of Speech,” Proc. IEEE Int'l Conf. Acoustics, Speech, and Signal Processing (ICASSP '93), Apr. 1993.
[28] W. Verhelst, “Overlap-Add Methods for Time-Scaling of Speech,” Elsevier Speech Comm. J., vol. 30, no. 4, pp. 207-221, Apr. 2000.
[29] M. Demol, W. Verhelst, K. Struyve, and P. Verhoeve, “Efficient Non-Uniform Time-Scaling of Speech with WSOLA,” Proc. Int'l Conf. Speech and Computer (SPECOM '05), Oct. 2005.
[30] SIPfoundry, sipXezPhone—A New sipXtapi Based SIP User Agent, http://www.sipfoundry.orgsipXezPhone/, 2008.
[31] ITU-T, Perceptual Evaluation of Speech Quality (PESQ): An Objective Method for End-to-End Speech Quality Assessment of Narrow-Band Telephone Networks and Speech Codecs, ITU Recommendation P.862, Feb. 2001.
[32] ITU-T, The E-Model: A Computational Model for Use in Transmission Planning, ITU Recommendation G.107, Dec. 1998.
[33] L. Atzori and M. Lobin, “Speech Playout Buffering Based on a Simplified Version of the ITU-T E-Model,” IEEE Signal Processing Letters, vol. 11, no. 3, pp. 382-385, Mar. 2004.
[34] F. Liu, J. Lee, and C.-C. Kuo, “Objective Quality Measurement for Audio Time-Scale Modification,” Proc. SPIE Internet Multimedia Management Systems (IMS '03), pp. 208-216, Nov. 2003.
[35] Motorola Inc., Motorola Seamless Mobility, http:/www.motorola. com, 2008.
15 ms
(Ver 2.0)

Marketing Automation Platform Marketing Automation Tool