COST 273 "Towards Mobile Broadband Multimedia Networks"

1. COST 273 "Towards Mobile Broadband Multimedia Networks" Bulgarian participation

2. COST 273 (May 2001 - June 2005) is a successor of the following actions in the field of radio wave propagation and networks planning: • COST 207 “Digital Land Mobile Radio Communications”, Mars 1984-Sept 1988; • COST 231 “Evolution of Land Mobile Radio (Including Personal) Communications”, April 1989-April 1996; • COST 259“Wireless Flexible Personalized Communications”, Dec 1996-April 2000; • Launching of new Action, previewed for 2006-2010 Institute of electronics - BAS, Microwave Remote Sensing Lab.

3. INFO for COST 273 and the coming Action: • www.lx.it.pt/cost273 • Chairperson: Prof. Luis M. Correia, IT/DEEC - Torre Norte, Instituto Superior TecnicoAv. Rovisco Pais, P - 1049-001 LisboaPortugal; e-mail: luis.correia@lx.it.pt • Secretary: Vera de Almeida, vera.almeida@lx.it.pt • Chairperson of the coming Action: Prof. RobertoVerdone, university of Bologna, rverdone@deis.unibo.it Institute of electronics - BAS, Microwave Remote Sensing Lab.

4. Main objectives of COST 273: • to increase the knowledge on the radio aspects of mobile and wireless broadband multimedia networks; • to explore and develop new methods, models, techniques, strategies and tools that will give inputs to the development of systems beyond the 3rd generation mobile and wireless communication systems; • to contribute to the deployment of systems that are more or less standardized, like UMTS and WLANs. Institute of electronics - BAS, Microwave Remote Sensing Lab.

5. Structure and activity of COST 273 • WG1: RADIO SYSTEM ASPECTS • WG 2: PROPAGATION AND ANTENNAS • SWG 2.1: MIMOchannelmodel • SWG 2.2: Antenna performance of Small Mobile terminals • SWG 2.3: Channel Measurements • WG3: RADIO NETWORK ASPECTS • SWG 3.1: Mobile Radio Networks Reference Scenarios Institute of electronics - BAS, Microwave Remote Sensing Lab.

6. Structure and activity of COST 273 (con’d) • Three MC meetings per year • One joint workshop per year • One Temporary Document per year per participating institution Institute of electronics - BAS, Microwave Remote Sensing Lab.

7. Bulgarian institutions that have expressed interest in participation in COST 273 • Institute of electronics – BAS • Institute of information technologies – BAS • Technical University - Varna Institute of electronics - BAS, Microwave Remote Sensing Lab.

8. Participation of IE-BAS • Areas of contribution (WG 2: Propagation and Antennas): • 1) improvement of propagation models for the planning of cellular networks in real environments; • 2) investigation of propagation models in strongly varying environment. Institute of electronics - BAS, Microwave Remote Sensing Lab.

9. Participation of IE-BAS (con’d) • The Parabolic Equation method combined with numerical techniques is applied to study the influence of tropospheric ducting phenomenon on microwave propagation. Studied are: • the influence of surface-based ducts on microwave propagation in short ranges (up to 3 km); • the influence of duct parameters changes (range dependent ducting); • the combined effect of terrain and ducting on path losses at UMTS frequencies. Institute of electronics - BAS, Microwave Remote Sensing Lab.

10. Participation of IE-BAS (con’d) • Results and discussion: influence of surface-based ducts in short ranges Fig. 1 showspath loss results for a 70 m surface- based duct, f=2 GHz, hr=10m, antenna beam-width 40 (without tilt) and different ht: a) ht=20m (the curves are shifted of -30 dB from their real position); b) ht=30m (no shift); c) ht=50m (the curves are shifted of +30 dB); d) ht=60m (the curves are shifted of +60 dB).Red curves - under ducting, black curves- standard troposphere. It is clearly seen that there is a shift of the location of the interference maximums under ducting in comparison to the standard troposphere case. Institute of electronics - BAS, Microwave Remote Sensing Lab.

11. Participation of IE-BAS (con’d) • Results and discussion: influence ofrange dependent ducting Fig. 2 shows path loss for f=2 GHz, zt=25 m, zr=10 m and: a) range independent surface-based duct with zd=100m, dM=60-units over the entire distance of 10 km;b) surface-based duct with zd=100m, dM=60-units at the transmitter and standard troposphere at distance of 2 km;c) surface-based duct with zd=100m, dM=60-units at the transmitter and standard troposphere at distance of 5 km. Institute of electronics - BAS, Microwave Remote Sensing Lab.

12. Fig. 3 shows the combined effect of terrain and ducting for f =2167.4 MHz (last channel carrier frequency from the UMTS WCDMA-FDD downlink frequency band), zt=30 m, antenna half power beamwidth 0=20, antenna tilt s=00; Fig. 4 stays for standard troposphere. Fig. 5 reports the path loss difference for the shadowed zone and the slope after it. • Fig.5Path loss for a receiver situated in the first 2 m above the surface for the terrain profile from Fig. 3: a) under ducting, b) under standard troposphere Fig. 3Path loss under ducting Fig. 4 Path loss for standard troposphere Institute of electronics - BAS, Microwave Remote Sensing Lab.

13. Participation of IE-BAS (con’d) • Conclusion • The proposed simulation procedure encompasses simple duct models with statistically averaged duct parameters based on real data and sophisticated propagation prediction method. • The reported examples show once again the need of implementing more precise propagation prediction techniques in the communications links planning tools (especially under complicated environment conditions) and the PE method is seen as one of these techniques able to provide quantitative results. • Clearly seen is the need of global climatology on ducting. Institute of electronics - BAS, Microwave Remote Sensing Lab.

14. Contacts: • Irina SirkovaInstitute of electronics-BASMicrowave Remote Sensing Lab.Blvd. "Tzarigradsko chaussee" 72Sofia 1784, BULGARIATel. +359-2-7144/567E-mail: irina@ie.bas.bg Institute of electronics - BAS, Microwave Remote Sensing Lab.

15. Thank you for the attention Institute of electronics - BAS, Microwave Remote Sensing Lab.