1. Paradise Holiday Resort, Bagamoyo, Tanzania 14-16 November 2007
School of Electrical and Information Engineering University of the Witwatersrand, Johannesburg
The Impact of Radio Channel Variability on Broadband Throughput Rates in Different Parts of Tanzania by
Peter Chitamu and Teddy Mwakabaga
Centre for Telecommunications Access and Services
School of Electrical & Information Eng.
The University of the Witwatersrand, Johannesburg
Tel:
Web:
5th International Conference on Open Access
Paradise Holiday Resort, Bagamoyo, Tanzania November 2007
Chitamu & Mwakabaga
5th International Confernence on Open Access

2. 5th International Confernence on Open Access
Outline
Introduction
Problem statement
Underlying network capabilities for ICT Services
Prevailing conditions in Tanzania
System Modelling
Results and Discussions
Summary & Conclusions
Chitamu & Mwakabaga
5th International Confernence on Open Access

3. 5th International Confernence on Open Access
ICT Services
What
has
Changed?
Chitamu & Mwakabaga
5th International Confernence on Open Access

4. Connectivity Challenges
ICT services require different underlying network capabilities
Capacity (Number of simultaneous connections)
Reach / Coverage
Throughput (bps)
Other considerations based on above
Transmission errors
Connection delays (Network latency)
Chitamu & Mwakabaga
5th International Confernence on Open Access

5. Multimedia Connectivity for the new User
Global
Connectivity
&
Content
Distribution ?
Internet
(IPnet)
Multi-Service
Net
Personal
Multimedia Gateway
PSTN
Monitoring
Station
Residential or SOHO
Chitamu & Mwakabaga
5th International Confernence on Open Access

6. Fixed-Mobile Access Configurations Example
Operator
Network
802.1x Hot Spot
SOHO
Tele-Working
Chitamu & Mwakabaga
5th International Confernence on Open Access

7. Convergence (Integrated) Services
ICT Services require a flexible network to cope with wide ranging requirements
Chitamu & Mwakabaga
5th International Confernence on Open Access

8. 5th International Confernence on Open Access
Provided
Service
Video Conferencing
Video Telephony
Tele-shopping
TDD
especially
Suited for
Asymmetrical
Services and
small area
coverage
FDD
especially
Suited for
Symmetrical
Services and
Wide area
coverage
Electronic Newspaper
Images / Soundfiles
Tele-banking
Financial Services
Data Base Access
Information Services
FDD / TDD
Voice
10 kbps
100 kbps
1 Mbps
10 Mbps
Question: Who needs what ?
Chitamu & Mwakabaga
5th International Confernence on Open Access

9. 5th International Confernence on Open Access
Main Classification is Error and Latency Tolerance
Lea Skorin-Kapov, etal,”Analysis of End-to-End QoS for Networked Virtual Reality Services in UMTS”, IEEE Comms. Mag. April 2004, pp
Chitamu & Mwakabaga
5th International Confernence on Open Access

10. Telecomms. Connectivity Major Events
All-IP
2006
1986
1991
2002
Fixed-Line
Fixed-Line
Mobile (1G)
(More fixed)
Fixed-Line
Mobile (1G & 2G)
(Fixed declining)
Fixed-Line
Mobile (2G & 3G)
(More Mobile)
Voice on PSTN
Data on PDSN
Broadcasting
Voice on PSTN
Voice on 1G
Data on PDSN
Broadcasting
Inter-working
PSTN & PDSN
(Packet &
Circuit Switching)
Broadcasting
Convergence
PSTN & PDSN
Broadcasting
(Limited)
Fixed &
Mobile
Convergence
Separate Voice from Data Paradigm
Multimedia Communication
Chitamu & Mwakabaga
5th International Confernence on Open Access

11. 5th International Confernence on Open Access
Problem
Statement
Chitamu & Mwakabaga
5th International Confernence on Open Access

12. 5th International Confernence on Open Access
What is the problem?
Coverage
Different operating areas impose different coverage requirements
For low density users and hilly areas, operators has to build many sites to meet coverage requirements which increases cost of service provision
Data Rates
Achievable data rates in an area are directly linked to the quality of the reception
Chitamu & Mwakabaga
5th International Confernence on Open Access

13. Problem: How to guarantee high data rates over large coverage area
Chitamu & Mwakabaga
5th International Confernence on Open Access

14. 5th International Confernence on Open Access
M El-Sayed and J Jaffe, ”A View of Telecomms. Network Evolution”, IEEE Comms. Mag., Dec 2002, pp
Chitamu & Mwakabaga
5th International Confernence on Open Access

15. 5th International Confernence on Open Access
System
Modelling
Chitamu & Mwakabaga
5th International Confernence on Open Access

16. Understanding of operating environments in Tanzania
Propagation measurement campaign carried out
Path loss models in representative areas of Tanzania
Multipath delay spread
Dense Urban, Urban, Sub-Urban, and Rural
This information used to investigate how operating environment will impact on the currently broadband access networks
iBurst, cdma2000 EV-DO and UMTS - HSDPA
Chitamu & Mwakabaga
5th International Confernence on Open Access

17. Link Budget vs Data Rate
PT(max)
PT(min)
PR(max)
Dynamic
Range
Quality of Received Signal
PR(min)
Distance
Chitamu & Mwakabaga
5th International Confernence on Open Access

18. Example: Propagation Environments
Soni
Ngudu, Mwanza
Njombe
Mombo
Chitamu & Mwakabaga
5th International Confernence on Open Access

19. 5th International Confernence on Open Access
Operating Environments make certain technologies very expensive to use outside Cities
Chitamu & Mwakabaga
5th International Confernence on Open Access

20. 5th International Confernence on Open Access
Scatter Plots
Chitamu & Mwakabaga
5th International Confernence on Open Access

21. Multipath selected Results
-6 dB
Chitamu & Mwakabaga
5th International Confernence on Open Access

22. Multipath selected Results
-6 dB
Chitamu & Mwakabaga
5th International Confernence on Open Access

23. Multipath selected Results
Pre-Cursors and Post-cursors
Nearby echos and a group from far
Chitamu & Mwakabaga
5th International Confernence on Open Access

24. Average path loss profiles
PL(d) [dB] = PL(do) nMF log(d/do) + σ
Flat terrain with light vegetation (e.g. Mwanza)
Undulating landscape, with moderate vegetation (e.g. Njombe, Iringa, many parts of Morogoro)
Hilly and heavily forested (Lushoto, USA River)
Chitamu & Mwakabaga
5th International Confernence on Open Access

25. 5th International Confernence on Open Access
Results
&
Discussions
Chitamu & Mwakabaga
5th International Confernence on Open Access

26. 5th International Confernence on Open Access
Assumptions
Networks not loaded to influence coverage
Use average path loss models from propagation measurements
Target BER of at least 10-6 for data rate of 500 kbps and 1.5 Mbps
No link improvements through diversity, adaptive modulation, etc
Only physical network speed as influenced by Eb/No specification and no flow or error control mechanisms applied
Chitamu & Mwakabaga
5th International Confernence on Open Access

27. Impact of Data Rate Variability
Chitamu & Mwakabaga
5th International Confernence on Open Access

28. 5th International Confernence on Open Access
EV-DO at 800 MHz
Chitamu & Mwakabaga
5th International Confernence on Open Access

29. 5th International Confernence on Open Access
iBurst at 1790 MHz
Chitamu & Mwakabaga
5th International Confernence on Open Access

30. 5th International Confernence on Open Access
HSDPA at 2100 MHz
Chitamu & Mwakabaga
5th International Confernence on Open Access

31. 5th International Confernence on Open Access
Summary
To make ICT Services widely accessible, the issue of connectivity platforms needs to be carefully considered
Tanzanian market is cost conscious
Understanding of the operating environments enable network designers to optimised Coverage, Capacity and throughput to meet the requirements for the wide range of ICT services
Tanzania operating environment are mostly coverage limited with users in undulating and hilly terrain.
More work needs to be done to understand how operating environments influence both cost and type of ICT services that can be cost-effectively offered in different areas of Tanzania
Chitamu & Mwakabaga
5th International Confernence on Open Access