Wireless Network Design: Optimization Models and Solution ...

15 Major Trends in Cellular Networks and Corresponding Optimization Issues 369
mechanism using Forward Error Correcting Code (FEC) and bulk acknowledgements.
According to [31], with these enhancements distances from 10 to 100 km
can be achieved, and a 2 to 5 fold improvement in TCP/UDP throughput has been
observed in a real-world deployment compared to the best achievable throughput by
conventional 802.11 MAC.
The primary cost benefit stems from the use of low cost and low power single
board computers, high-volume off-the-shelf 802.11 wireless cards originally intended
for industrialized markets, and low cost towers. In addition, the typically
lower incomes lead users to share computer terminals (e.g., Internet kiosks) to amortize
the relatively high cost of the devices and network connection. Thus, the cost
barrier of data terminals capable of leveraging the WiFi is lowered.
The authors also report a variety of non-technical problems encountered in the
deployments. The installation, maintenance, and servicing costs turned out to be
larger, due to lack of local technical expertise, equipment availability, and logistics.
They identified the need for production-quality solutions, and the hardware and
software must be robust, user friendly, and simple to install, maintain, and manage.
Local partners must be trained as well. Another barrier is local telecommunication
regulation, which is hindered by limited technical staff, “imperfect” government,
and the presence of local incumbent monopolies. Problems related to the use of
VoIP over unlicensed frequencies include restrictions on using VoIP (favoring local
telecom monopolies), licensed or even restricted frequency bands that are unlicensed
everywhere else in the world, and unregulated wireless usage resulting in
significant same-band interference.
The WiLDNET approach is potentially more disruptive, as it relies on unlicensed
frequency bands and therefore does not depend on a CSP in the traditional sense.
It can be setup by grassroots organizations [32]. This is important for those rural
areas which are less enticing to CSPs due to the low density and income of users.
15.8.2 Value
Another approach, not mutually exclusive of the previous one, is to provide higher
value through services tailored to the needs and constraints of the village population.
Examples include telemedicine, mobile commerce, mobile banking, and mobile access
to public services.
Telemedicine can help to address the severe shortage of trained doctors and
nurses in rural areas, by providing villagers with remote access to health care. This
is enabled by affordable connectivity reaching the villages. The deployment of an
intranet network in South India between hospitals and rural vision centers based
WiLDNET is described in [33]. In the vision center model, doctors remain at the
hospital but interact with patients over the communication network. A vision center
is a room in the village equipped with basic ophthalmic equipment and a PC
with a webcam, and staffed by two personnel who do not have a degree or a broad
technical skill set. The local personnel perform some basic vision tests, present the