On the Design of Inclusive Ubiquitous Access
Amos Nungu
Telecommunication Systems Lab
KTH Royal Institute of Technology
Forum 120, 164 40 Kista, Sweden
Email: amnungu@kth.se
Robert Olsson
Telecommunication Systems Lab
KTH Royal Institute of Technology
Forum 120, 164 40 Kista, Sweden
Email: robert@herjulf.net
Bj¨ orn Pehrson
Telecommunication Systems Lab
KTH Royal Institute of Technology
Forum 120, 164 40 Kista, Sweden
Email: bpehrson@kth.se
Abstract—The development towards ubiquitous network access
requires innovative solutions to get remote areas included, espe-
cially rural areas of developing regions. The challenges include
robustness of network components, poor or non-existent power
supply and sustainable business models. We argue that large
scale user-driven community networks are becoming technically
viable to deploy in areas that are short of supply of telecom-
munication services due to little or no commercial interest.
To support this claim, we discuss the design of key network
elements and careful power management based on alternative
energy sources and storage. We also provide a status report
from ongoing field-tests regarding provisioning of broadband
network services in Serengeti, Tanzania, and outline briefly our
strategy to achieve sustainability. On the technical side, we first
discuss an affordable, high-performance, low-effect router based
on open source software and standard off-the-shelf hardware
offering both copper and fibre links. Our design is capable of
forwarding more than 700kpps at 22.3W. The power consumption
is considerably less than all alternatives in our comparison. Then
we discuss power management and the use of batteries and super-
capacitors as backup and storage solutions.
I. I NTRODUCTION
In the knowledge society, ubiquitous access to communica-
tion networks and services, broadband as well as mobile, is
becoming a prerequisite to keep up with your peers, whether
you are an individual, an organization or a country, wherever
you are based. Broadband networks have also been identified
by the UN Broadband Commission [1] as uniquely power-
ful tools for achieving the Millennium Development Goals.
Ubiquitous access is thus a social and economical challenge,
not only a technical. There are many areas that are under-
served due to the perceived business risks. In most of these
areas, there is demand but no supply since the revenue streams
are unpredictable and the costs high due to the investments
required in infrastructure, such as optical fibre cables, reliable
electrical power and a complete commercial supply chain.
In developing regions, the risks may also include political
components due to unstable policies and under-developed
regulatory frameworks.
Even though many rural areas enjoy access to mobile phone
networks, few of them provide broadband services due to lack
of broadband communication infrastructure. Local broadband
communication services are mostly non-existent while Internet
access is sometimes provided via narrowband VSATs connec-
tions through community access points (telecenters).
Our research is focusing on first mile rather than last
mile strategies to bridge the digital divide by stimulating the
development of local broadband markets, starting from the
end-users. We advocate the creation of local community-driven
broadband islands, meaning that the uplink, if it exists, is
narrowband, until the necessary upstream infrastructure be-
comes available. Thanks to the availability of easy-to-use and
affordable high-performance standard PC hardware and open
source software, large scale user-driven community networks
are becoming technically viable to deploy in areas that are
short of supply of telecommunication services due to little
or no commercial interest. However, there are observations
regarding the availability of power supply in rural developing
regions [2], [3]. The challenge is therefore not only about
minimizing the demand for power to reduce the environment
foot print and save costs. It is also about managing the
available power to be able to provide services when users
need them, whether this is continuously 24/7 or according to
a schedule, and to manage backup power storage optimally.
As a service provider, you may not have access to any
power infrastructure at all or you might have to manage
planned rationing schemes, unplanned blackouts, brownouts,
destructive transients, etc. Consequently, energy awareness and
power management may have to become integrated in the
communication systems architecture and even in application
systems to allow user-control. Design of low-effect network
elements is one approach.
In this paper, we discuss our work on an affordable high-
performance, low-effect router based on open source soft-
ware and carefully selected standard off-the-shelf hardware
offering both copper and optical fibre links, and a power
management system designed to manage alternative energy
sources and storage. The current version of the router is
capable of forwarding more than 700kpps at 22.3W. This
power consumption is considerably less than all alternatives in
our comparison. We also report on ongoing field-tests based
on the use of the current version of this router for provisioning
of broadband network services in Serengeti, Tanzania [4].
We acknowledge earlier work on software routers such
as [5], [6], [7], [8]. However, the context and design goals
were different. To our knowledge, none of them considered
robustness and low-power consumption as key factors in their
designs. In addition, our work considered viable options for
power backup and storage using ultra-capacitors.
Our contribution in this paper is in the design of a low-
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