Diary of Thursday, 24th February 2005

Prepared by: Chimon Alberic

1rst Session and LAB
Lecturer: Tomas Krag
Period: 9 AM to 16:30 PM
Topic: Introduction to Mesh network.

Tomas Krag started his lecture by defining what Mesh topolog is all about by giving definition and also talks about advantages , disadvantages and protocols of Mesh technology.

In fact ,Tomas Krag established the difference between full mesh topology and partial one mesh topology .In full topology , each node is connected directly to each of the others but the partial mesh topology , nodes are connected only somes, not all, off the others nodes.

The Advantages of Mesh technology are:

• Self organizing
• Node ranging
• Different ways to get the source
• Scalable
• Self healing
• Affordable
• Useful in high noise environment

This topology has also his own disadvantages:

• No DHCP
• Vulnerable to a hacks
• Scalability issues with single half-duplex radios
• Difficult to proper authentication
• No single standard

From 10:30 AM, we started a real practical Lab with Tomas and deploy a Mesh topology.

The lab was to connect Metrix Access Point using OSLR protocol to optimized link state routing. All groups managed to hook up to the Mesh network via the OSLR protocol.

2nd Session
Lecture:
Time 4.30 to 6 :30 PM
Lecturer: A. Sanchez
Topic: Long distance HF links

Sanchez explain how the "Hispano-American Health Link" program (EHAS in Spanish), develop low-cost telecommunication systems and information services specially designed for rural primary healthcare personnel from isolated areas in developing countries. Based on HF and linux software development , the EHAS program was successful and it can be a show case in term of low cost technology experience in development countries as research and development on information services systems suited to the needs of health personnel .

3rd Session
Time 7.30 to 8.30 Hrs
Topic: Lab : Preparation of the long-distance field activities
Lecturers: E.Pietrosemoli , C.Fonda & M. Zennaro

This evening was entirely devoted to the excellent preparation of long-distance field activities.

Carlo and his team Started off by highlighting important parameters and factors that must be considered when planning a wireless link and theoretical calculation of path loss, physical position and the others parameters consideration as the following:

• Link margin: this is a measure of link quality of the equipment
• Minimum RSL: this is the minimal Receiver Signal level in dB (also known as Sensitivity)
• Range: how far the signal can reach
• Availability: how reliable is the link

This preparation was very helpful for the following day of activity.

Chimon Alberic
African Virtual University
ICT Department
e-mail : achimon@avu.org
web site : www.avu.org