Ceragon is
exhibiting at West and Central Africa Com, taking place today
at King
Fahd Palace in Dakar, Senegal.
John Earley, the President
of Ceragon Africa and Middle East is our guest
blogger for the week. Today he shares his views on how “Microwave
Expansion Improves Connectivity for Africa”
Africa is connected directly, telecommunications-wise,
to Europe, South America, and the Middle East via the subsea cables that were
laid in the last decade and that surround the continent. This, of course,
enables African governments, multinational corporations and other organizations
to open up African communications to the rest of the world. However, there is
still the problem of connecting up cities, towns and villages, especially those
that are not very close to the subsea cables, so that the bulk of the
population of African countries can enjoy the benefits of the Internet and
international data communications services.
Terrestrial fibre cable has traditionally been
considered the long-term solution for Africa’s connectivity demands. At the
start of 2010, there were more than 300Gbps of Internet capacity in place on
the African continent. By the end of that year, Internet traffic had already
grown an additional 70% to more than 500Gbps. Where available, fibre
accommodates this growth so, governments and private operators have rolled out
many kilometres of fibre cable both internally and across national borders to
bring networks together and to establish and improve connectivity with the
subsea cables. But it seems that even after more than five years and
hundreds of thousands of kilometres of deployed fibre, connectivity is still a
problem.
The African environment makes fibre deployment difficult
for a number of reasons.
- Fibre is expensive to deploy and operate especially over long distances
- Breaks in the Fibre, malicious or accidental, are a daily occurrence
Fibre Deployment.
Greenfield fibre deployment is a time-consuming and expensive activity. The
costs for trenching and deploying fibre increase rapidly with distance.
Right-of-way permits and the labour-intensiveness of trenching add
significantly to the cost and the time required. Fibre requires significant
supporting equipment. For example, network interface cards (NICs) for fibre
cables can cost $1,000 each and a fibre network requires thousands of
them. For connecting highly populated areas, fibre deployment can be
justified. However, as Africa comprises many large countries with population
centres separated by vast distances, not to mention numerous remote areas, Fibre
deployment becomes exceedingly expensive.
Fibre Breaks. After
a fibre break, in the best cases, severely restricted back-up services to fibre
routes are dimensioned to carry only essential voice and signaling traffic leaving the
growing IP-based data services at risk along with the revenues they
generate. In the worst cases, fibre breaks destroy connectivity
completely for unacceptably long periods of time. With vast road
construction, poor environmental management and erratic observance of planning
procedures, no country in Africa is immune. In Nigeria alone, there are, on
average, fourteen fibre breaks per 100km per year leading to a colossal 2,200
hours of network down-time! When a fibre break occurs, the expectations that
customers have built up for accessibility and quality of service are
destroyed.
Africa is returning to microwave.
Although they neglected long-haul microwave in favour of
fibre, African network operators are re-thinking their strategies. Where
microwave was once considered a less desirable technology than fibre, operators
are now seeing significant advantages.
Microwave is particularly suitable to the African
environment due to technology advances, lower deployment costs, ease of
maintenance, and practical backup strategies. For example, Celtel has installed
a long-haul microwave link to improve communications between Uganda and
Tanzania. A new microwave link now connects Tangiers, Morocco with Tarifa,
Spain.
Advances in Capacity.
Today’s microwave technology provides impressive long-haul capacity. Where
outdated routes were previously limited to two or three STM1s, they now carry
capacities measured in gigabits. Innovative technologies, like advanced
modulation and multi-channel bandwidth control empower network
operators to provide true high capacity on long-haul routes. Today’s long-haul
microwave provides abundant capacity far in excess of Africa’s current and
predicted demand.
Advances in Reliability.
Where inclement weather and other types of interference used to be mitigating
factors in microwave link availability, leading microwave equipment vendors are
now able to keep their long-haul transmission links functional even in
transient fading conditions. For example, Ceragon Networks’ systems sense the
quality of the transmission link and can automatically decrease the modulation technique
in case of degraded signal quality due to interference or other microwave
propagation problems. So, if a microwave transmission is humming along at
maximum capacity and it suddenly encounters fading, the Ceragon microwave
system automatically steps down the modulation to lower levels until the
transmission network maintains the requisite level of reliability. The traffic
is distributed over all carriers using Multi-carrier Adaptive Bandwidth
Control (ABC), so, when one carrier is affected by reduced modulation, the
link distributes traffic to the remaining carriers making the link appear as a
single dynamic, high-capacity pipe. As the transient problems disappear, the
resilient microwave system automatically re-applies more efficient modulation
techniques to regain full capacity. All of this occurs automatically with
split-second timing and without human intervention.
Deployment Costs and Speed.
Long-haul microwave links are significantly less expensive and speedier to deploy
than fibre. Right-of-way issues and expensive trenching are avoided while
complete microwave networks can be implemented economically in just weeks
reducing the operator’s time-to-revenue and service provision. Unlike fibre,
microwave deployment costs do not increase with distance. Long-distance hops of
20, 50 or even more than 100 kms are practical to implement.
Microwave is an excellent fit for large African
countries with vast territories between population centres and is enjoying a
resurgence in Africa.
You are invited to attend West and Central Africa Com, taking place today at King Fahd Palace in Dakar, Senegal.
For more information, please visit our
website www.comworldseries.com/wcafrica
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