Wireless Communication for Previously Disadvantaged

Secondary Schools in Grahamstown, South Africa

Ingrid Brandt Alfredo Terzoli

Cheryl Hodgkinson-WilliamsDepartments of Computer Science and

EducationRhodes University

Overview

ICTs in Education School Wireless Networks 802.11 for Grahamstown schools

Painting a picture IEEE 802.11 The Experiments Discussion

Other wireless solutions Conclusion

ICTs in Education

Factors which accompany successful implementation of ICTs in schools network connectivity structured and continuous

programmes to educate teachers Low teledensity in some rural areas Expense of wired infrastructure

School Wireless Networks (1) Advantages to schools having some

form of connectivity Interactivity Immediacy Currency Accessibility

While it doesn’t alleviate all problems, Internet access can help alleviate access to information

Networking people

School Wireless Networks (2)

Other school wireless projects Ulwazi CSIR projects

Limiting legislation Provision Frequency bands - ISM

Grahamstown Schools – Painting a picture (1)

Only 8.8% of EC schools have computers and 4.5% have PCs for teaching and learning

Grahamstown is found in EC, population 120 000, diameter 10-12km

13 Secondary schools 3 Independent schools (IS) 6 Former Department of Education and

Training (FDET) 3 Former Model C schools (FMC) 1 Former House of Representative (FHoR)

Grahamstown Schools – Painting a picture (2)

Cost limits E.g. Annual school fees at

FDET3 Section 21

Companies

802.11 for Grahamstown Schools – IEEE 802.11 (1)

1/3 of secondary schools not in range of DSL

Investigation of the use of 802.11b- and 802.11g-bashed wireless LAN technologies as a means of connecting these schools

802.11 for Grahamstown Schools – IEEE 802.11 (2)

IEEE 802.11 standard is part of a family of standards for local and metropolitan area networks

Defines the protocol and compatible interconnection of data communication equipment via air, radio or infrared in a LAN using CSMA/CA

802.11 is well documented, standardised, low cost and easy to deploy

802.11 for Grahamstown Schools – The Experiments (1)

Initial tests with Symbol AP and 19dB gain Flat panel antenna 802.11b Sugar Loaf Hill results Nombulelo Water Tower/ Makana’s Kop

results

At the Monument D-Link AP (b/g compatible) 8 dB omni directional antenna

The wireless Network Topology using the D-Link APs

802.11 for Grahamstown Schools – The Experiments (2)

802.11b/g with D-Link AP and 12dB yagi at client sites in town Slower transfer rates Increased delay Increased packet loss

Nombulelo Water tower 22 dB gain directional grid antenna facing

Monument Association on layers 1 + 2, but no IP

traffic

802.11 for Grahamstown Schools – The Experiments (3)

Lots of interference + lower maximum transmission power (63mW vs. 100mW)

New Ciscos + new grid dish Initial tests at the water tower see

transfer rates of 6Mbps Improved transfer rates and more

consistent delay experienced at town client sites

Round-trip time (ms) vs. Time

D-link AP in 802.11g

Cisco AP in 802.11g

Town Clients

Throughput in Mbps

Conclusion

Wireless connectivity has the potential to make a difference to SA schools

Legislative changes are needed to create an competitive industry where Encourage innovation Bridge the digital divide in Education

Biggest problems for schools are Lack of Infrastructure and associated high

costs Lack of bandwidth and associated high costs

Wireless Communication for Previously Disadvantaged

Secondary Schools in Grahamstown, South Africa

Funded by the NRF and the EEE Trust