990 IEICE TRANS. COMMUN., VOL.E87–B, NO.4 APRIL 2004 PAPER Video over TETRA Employing MPEG-4 Visual Coding Standard Yoong-Choon CHANG † a) and M. Salim BEG †† , Nonmembers SUMMARY Video transmission over Terrestrial Trunked Radio (TETRA) mobile channel employing MPEG-4 visual coding standard is proposed in this paper. Detail parameters of the proposed systems are dis- cussed in this paper. Performance of the proposed systems was evaluated in Average Peak Signal to Noise Ratio (APSNR) versus Signal to Noise Ratio (SNR) and Bit Error Rate (BER). In particular, the video quality that can be achieved at different channel conditions and employing different com- binations of MPEG-4 visual error resilient tools is presented in this paper. Results obtained show that higher video bitrate does not necessarily lead to higher video quality at the receiver as the received video quality depends on the bit error pattern or the number of error free video packets. key words: multimedia coding, MPEG-4, wireless video communications, TETRA 1. Introduction With the rapid growth and deployment of mobile and wire- less communication systems during the last decade, the need for transmission of multimedia information over such links has become an important application requirement. Trans- mission of video is particularly challenging in view of the high data rate of raw video. Video compression techniques are therefore to be used to reduce the bandwidth require- ments and enable the transmission of video information over bandlimited wireless channels. On the other hand, wireless and mobile channels are typically noisy and suffer from a number of channel degra- dations due to multipath reflections and fading. The effect of channel errors on compressed video bit stream is partic- ularly severe, due to the manner in which the video is com- pressed and coded. Hence it is extremely critical to employ error resilient coding techniques in order to get robust trans- mission of coded video data, and is therefore the motivation behind the work presented in the paper. A number of techniques have been proposed to attempt to reduce the sensitivity of compressed video data to cor- ruption [1]. Many of these techniques focussed on H.263 for low bit rate applications. H.263+ now has a wide vari- ety of error resilience options [2]. The advent of MPEG-4 recently has introduced a wide range of new features [3]. Transmission of video over practical public mobile sys- Manuscript received May 9, 2003. Manuscript revised October 21, 2003. † The author is with the Faculty of Engineering, Multime- dia University, Jalan Multimedia, 63100, Cyberjaya, Selangor, Malaysia. †† The author is with the Department of Electronics Engineering, Aligarh Muslim University, Aligarh, India. a) E-mail: ycchang@mmu.edu.my tems and protocols have been reported recently by some re- searchers. Transmission of compressed video over GSM has been proposed in 1996 [4] but due to the limited data traffic rate of GSM, which is up to a maximum of 9.6 kbit/s, the proposed system was only on transmitting still image over GSM channel. In 1999, video transmission over General Packet Radio Services (GPRS) was proposed [5]. In 2001, NTT Docomo, Japan has launched real-time visual and au- dio communications through third generation (3G) mobile networks. This paper however describes the proposed implemen- tation of video transmission over a Terrestrial Trunked Ra- dio (TETRA) which is a standard for Private Mobile Radio (PMR) [6], [7]. It may be noted that current TETRA phone only supports voice transmission function and TETRA phone with video transmission function is still under re- search and development to a large extent, and this is the motivation behind the work being reported here. A potential application for future TETRA phone with video transmis- sion capability is the traffic accident incidence. A TETRA phone with integrated camera could be used to transmit live video from the traffic accident scene back to the police and ambulance services that could then accurately assess the sit- uation and dispatch the relevant medical equipment and aid. The system being proposed by the authors in this paper has the following advantages which cannot be achieved with some of the previously proposed video over mobile systems: i) Group calls: The proposed system will be able to send video to other users in the same area. ii) Fast call set-up: The proposed system will be able to send video to other TETRA user almost immediately, with- out delay. This function is particularly useful and important during emergency situation. iii) Coverage: In the case where cellular service is dis- rupted during a nationwide power failure or due to some other reason, the proposed system will be very useful. Con- sidering a bank raid case during such type of circumstances, police officers away from the scene can receive live video scene of the bank with the help of the police in the bank through the proposed video over TETRA system. Details of video transmission over TETRA employing MPEG-4 visual coding standard is proposed in this paper. Advantages of the proposed system compared with previous video over mobile systems have been presented briefly in the paper. In Sect.2, an overview of TETRA and MPEG-4 is given. Section 3 presents the proposed systems, followed by details of experiment setup in Sect. 4. Results are presented