LISTSERV mailing list manager LISTSERV 16.5

Help for AFRIK-IT Archives


AFRIK-IT Archives

AFRIK-IT Archives


AFRIK-IT@LISTSERV.HEANET.IE


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

AFRIK-IT Home

AFRIK-IT Home

AFRIK-IT  March 1999

AFRIK-IT March 1999

Subject:

Fw: Wireless Networking in Africa

From:

Shady Kanfi <[log in to unmask]>

Reply-To:

African Network of IT Experts and Professionals (ANITEP) List

Date:

Fri, 12 Mar 1999 19:41:10 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (262 lines)

Afrik-ITers may be interested in this article which was distributed over a new mailing list called
'linux without borders.'

The article deals with setting up wireless LAN networks in universities (using Linux).

The new list deals with using Linux in resource-poor situations where people more often than not
share computers with others. (FYI: Linux is a particularly good operating system when it comes to
handling multiple users on a single computer)

To subscribe, send E-mail to: [log in to unmask] with the following line in the body of the message:

subscribe linux-without-borders

Cheers!
-Shady

---
Shady Kanfi
Program Officer, Bellanet International Secretariat
Ottawa, Canada
[log in to unmask]

-----Original Message-----
From: Enrique Canessa <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: March 12, 1999 8:42 AM
Subject: Wireless Networking in Africa


:Draft of Article appeared in "Linux Journal", Dec 1998.
:
:
:                        WIRELESS NETWORKING IN AFRICA
:                        -----------------------------
:
:      F. Postogna, C. Fonda, E. Canessa, G.O. Ajayi and S. Radicella
:
:       The Abdus Salam International Centre for Theoretical Physics,
:          Trieste 34100, Italy - E-mail: [log in to unmask]
:
:
:
:
:  Global connectivity in Africa is in an early stage due to installation
:costs, insufficient basic infrastructures, low quality of available
:telecommunication services and limited financial support.  The application
:of wireless technology then might become an effective choice to overcome
:some of these problems, at least within reduced areas and even if the
:transmission speed could be lower than the one achieved by wired networks.
:
:  Within an University campus, it is easier to install a radio link system
:than to dig around and place cables or expensive optical fibres.
:Furthermore, radio installations are easier to protect from external
:natural phenomena such as flood, landslide, etc.  At a first glance,
:wireless LANs look more expensive than wired LANs, but, in the long term,
:they have lower maintenance costs and are also relatively easy to
:configure.  The use of Linux and standard radiocommunication technologies,
:in conjunction with the many Linux software applications, facilitates even
:more this task.
:
:  With this picture in mind, the "Programme of Training and System
:Development on Networking and Radiocommunications" started in 1995 at The
:Abdus Salam ICTP, Trieste, Italy.  Since then, the objective of this
:Programme has been to provide technical assistance and training to
:academic and scientific institutions in developing countries in need to
:establish small area computer networks, and their connection to the
:Internet, either directly or through national networks.  Briefly described
:here are our experiences of wireless networking with Linux in Africa.
:
:  The Abdus Salam ICTP in Trieste, Italy, and Obafemi Awolowo University
:(OAU) of Ile-Ife in Nigeria, agreed to collaborate in the establishment
:and future evolution of a Pilot Educational and Research Computer Network
:at OAU.  Such a network, based principally on PC computers running Linux,
:today provides connectivity between several Faculties and Departments on
:the campus.
:
:  The training of technical staff on the hardware (PCs, cabling, radio
:techniques) and software (network and system administration) took place
:initially in Trieste.  The developmental and simulation work was completed
:in four months, ending in January 1996, when all the necessary equipment
:was sent to OAU. The system was installed in April 1996.  At this time
:some staff of other Nigerian Universities came to Ile-Ife in order to
:benefit from this exercise and meet Linux for the first time. Besides
:getting acquainted with the new technology, this experience led to further
:connections to the OAUNET. The campus network has been in operation since
:June 1996 without major problems being highly beneficial for the academic
:life of the University.
:
:
:
:                  THE FIRST CAMPUS NETWORK
:
:  As shown in the diagram of Fig.1, the wireless campus network (OAUNET)
:was planned on the basis of a radio system in the UHF band, initially
:involving three separate buildings with the capacity to rapidly being
:extended to other University structures.  The wireless link uses a Spread
:Spectrum Direct Sequence technique providing data transmission at 2Mbps.
:The so-called "Spread Spectrum" is a digital coding method in which the
:signal is transformed or "spread" so that it cannot be received by any
:receiver except the designated one which understands the transmitted
:signal code. It minimizes interference to other users and normally does
:not require an operation license in the ISM (International Scientific and
:Medical Band), depending of the regulation adopted by the country.
:
:  Inside each building an Ethernet 10-BASE 2 cabling structure is installed
:in order to keep the initial costs as low as possible (no hubs, less
:cable) and to ensure the local availability of spares (BNC), etc.  In each
:of these buildings, a Linux PC acts as "Faculty Server" and provides mail
:services for the local users and does routing to the backbone. This type
:of strategy has been selected to keep the user generated traffic local,
:and so reduce the access to the main backbone. All services are TCP/IP
:based to keep the system as standard as possible with Internet protocols,
:avoiding future modifications when a full connectivity might be provided
:to the University.
:
:  The academic network gateway and the main mailhost are located at the
:Department of Computer Science of the University. Due to national
:regulations and to the lack of a permanent connection to Internet, the
:gateway is linked to the Internet on a dial-up base (uucp) using an
:International Direct Dialing line to the ICTP computer network in Trieste,
:Italy. Software was developed by OAU staff with some assistance from ICTP
:to refine over the basic uucp mail transfer: a custom sendmail delivery
:program batches mail in intermediate-sized, BSMTP formatted files; these
:files are compressed as much as possible before being transferred over
:uucp.  To cope with telephone line instabilities, a uucp relay was placed
:in Lagos:  the uucp configuration takes cares of selecting either path,
:choosing automatically the one that works.
:
:
:
:                      STICKING TO LINUX
:
:  Previous in-house experiences with the Unix system (SunOS and SunSolaris)
:led us to test, within the Project, the commercial Solaris 2.4 (x86
:version) and Linux.  While this version of Solaris required specific
:hardware components to function on the available (486) PCs, Linux was
:found more flexible in terms of hardware compatibility and low memory
:requirements. On top of that, the possibility of having high quality free
:compilers and software applications, motivated us to continue using Linux
:to the present.  Only two years ago the alternative Windows NT was just
:starting to be popular around the world, so this possibility was not then
:considered. At that time, Linux was also unknown in the Nigerian academic
:world.  The main operating systems available there were MS-DOS & Windows
:3.1.
:
:  The Linux distribution chosen was the Slackware distribution.  Though more
:difficult to install than other distributions, right from the first trials
:the system configuration (start-up scripts, etc) was easier to locate,
:understand, manage and, most importantly, it was easy to teach.  After a
:whole cycle of Linux setup experiences and training, autonomous management
:of all aspects has became a reality.  Part of the system installed at the
:OAU is shown in the Picture.
:
:
:
:                    CAMPUS WIRELESS CONNECTIVITY
:
:  In order to achieve campus wireless connectivity, the requirements needed
:from the system administrator point of view were to have a network working
:all day and night long with the least possible human intervention, as well
:as to have a reasonable throughput (bandwidth). The technology adopted to
:do this job was, as mentioned above, Spread Spectrum.
:
:  The first attempts were implemented using Direct Sequence Spread Spectrum
:card which is supported by the Linux kernel.  Most recently an alternative
:Spread Spectrum equipment that does not require the Linux kernel support
:is being tested, not because of Linux unreliability, but because this new
:equipment instead of being an ISA card to plug in a PC, has an Ethernet
:interface. This configuration makes the installation of a wireless link
:much easier and flexible, because you can place the radio unit very close
:to the antenna (keeping attenuation very low) and connect it to the PC
:using a UTP cable. In the case on an ISA card the RF output is at the rear
:side of the PC and from there the antenna is connected. But due to the
:small output power and the attenuation of the cable it is not advisable to
:use more that 10m of coax. This new equipment uses a different spreading
:method called frequency hopping and provide a higher bandwidth.
:
:  The possibility of using packet radio technologies, which are very well
:supported and documented under Linux (AX-25 HOW-TO), were analyzed at the
:beginning of the Project.  However, due to the specific training required,
:the implementation of this technology was postponed. An advantage of the
:present Spread Spectrum installation, running since two years without
:major interventions, is that it is almost plug, play and go.
:
:  The local network is in fact stable and does not suffer from failure of
:primary main power supply, because of the standby generator availability
:and UPS facilities.  The number of registered users of the network
:increased from 150 in early August 1996 to about 290 in September 1996,
:with a number over 600 now.
:
:
:
:                       ON-LINE SERVICES
:
:  Campus-wide services such as e-mail and FTP, WWW, NFS are today available
:within the OAUNET.  As anticipated, connection to the rest of the world is
:done on a dial-up line so that only e-mail exchange is provided freely to
:the local users.  There is not limitation in the amount and size of the
:information being transferred on the campus.
:
:  Some of the communication applications like TALK or WRITE become important
:due to the poor performances of the local PABX.  For example, after the
:take off of the network, people that used to walk in order to speak with
:an administrative officer or a colleague are now enjoying the relax of a
:TALK between two building located a few kilometers apart.  To reduce
:bandwidth usage only "text"  based conferences tools are being
:implemented.  Hopefully, voice over IP will be also experimented in the
:future.
:
:  All of these new communication tools are certainly providing a
:revolutionary change in the local academic life.
:
:
:
:                            NEXT STEPS
:
:  The next phase of the wireless network requires the installation of other
:Internet services on the OAUNET. For example, arrangements are being made
:to provide connectivity to the Library and other Faculties such as
:Agriculture.
:
:  The success of the Ife experience stimulated cooperation with other
:Nigerian Universities. A large program of cooperation with the National
:Universities Commission for the establishment of a national academic
:network started in 1996 and it is still going on. Linux is one of the
:technical basis of this activity; on the other hand, the most interesting
:applications of radio till now have been in individual Universities. Among
:these, is the Bayero University (Kano) which decided to built up a link on
:a larger distance to connect the new campus with the old Campus of the
:University (about 9 Km).  This connection is implemented using a
:commercial wireless equipment and two Linux machines as routers, with one
:of them as the whole university mail server and uucp gateway.
:
:  Following these results a series of additional proposals have been
:received at our headquarter in Trieste.  The first of these new projects
:is being carried out in Ghana and collaboration with countries such as
:Democratic Republic of Congo, Ivory Cost and Morocco will start soon.
:
:  No doubt, these initial experiences with Linux in Africa are a proof of
:the success and reliability of Linux.
:
:
:
:                           Acknowledgements
:
:  This Programme is partially supported by the United Nations University
:(UNU).  Swisscomm has donated microwave links and several measurement
:instruments and equipment that constitute the foundation for the
:establishment of a laboratory which is being utilized for practical
:exercises in the framework of the Programme and the concrete field
:operations.
:
:Our appreciation also goes to Dr A. Nobile, one of the coordinators of the
:Programme, and Dr. E. Ekuwem, Mr. A. Maggi and C.E. Onime who are actively
:participating in this Project.
:
:
:                                 -oOo-
:
:
:

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

January 2012
December 2011
November 2011
March 2011
February 2011
January 2011
September 2010
June 2010
May 2010
April 2010
March 2010
February 2010
October 2009
September 2009
July 2009
June 2009
March 2009
February 2009
January 2009
November 2008
October 2008
August 2008
July 2008
April 2008
March 2008
November 2007
August 2007
July 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
November 2005
October 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
July 2001
June 2001
May 2001
April 2001
March 2001
February 2001
January 2001
December 2000
November 2000
October 2000
September 2000
August 2000
July 2000
June 2000
May 2000
April 2000
March 2000
February 2000
January 2000
December 1999
November 1999
October 1999
September 1999
August 1999
July 1999
June 1999
May 1999
April 1999
March 1999
February 1999
January 1999
December 1998
November 1998
October 1998
September 1998
August 1998
July 1998
June 1998
May 1998
April 1998
March 1998
February 1998
January 1998
December 1997
November 1997
October 1997
September 1997
August 1997
July 1997
June 1997
May 1997
April 1997
March 1997
February 1997
January 1997
December 1996
November 1996
October 1996
September 1996
August 1996
July 1996
June 1996
May 1996
April 1996
March 1996
February 1996
January 1996
December 1995
November 1995
October 1995
September 1995
August 1995
July 1995
June 1995
May 1995

ATOM RSS1 RSS2



LISTSERV.HEANET.IE

Secured by F-Secure Anti-Virus CataList Email List Search Powered by the LISTSERV Email List Manager