TV White Space Channel Allocation with
Simulated Annealing as Meta Algorithm
Bo Ye
ESBE, London South Bank Uni.
London SE1 0AA, UK
Maziar Nekovee
BT Research, Polaris 134 Adastral Park,
Martlesham, Suffolk IP5 3RE, UK
Anjum Pervez, and Mohammad Ghavami
ESBE, London South Bank Uni.
London SE1 0AA, UK
Abstract—When developing a TV White Space (TVWS) system
with the available TV spectrum after digital switchover, channel
allocation for TVWS devices to avoid interference becomes one
of the most challenging problems. In this paper, Simulated
Annealing (SA) is applied to solve the problem to minimize the
total interference. However, the performance of SA applied to
the problem depends on the appropriate choice of several key
parameters. Hence, all parameters are listed and experiments
with all possible combinations are done and the parameters that
perform best are chosen manually. Manual selection requires a
lot of experiments and is not effective. Therefore, an algorithm
using SA as meta algorithm is proposed to choose the parameters
automatically for SA. Finally the result of parameters selected
automatically is compared with the result of those selected
manually. We will show that automatic selection performs better
compared with manual selection.
Index Terms—Simulated Annealing, Hyper-heuristics Algo-
rithm, Channel Allocation, TV White Space.
I. I NTRODUCTION
The proposed switchover from analogue to Digital TV
(DTV) in the UK and elsewhere in Europe and the United
States has generated particular interest in cognitive wireless
networks strategies to find new solutions for Radio Resource
Management. After the switchover has been completed, a
significant amount of RF spectrum within the existing TV
band which are also known as TV White Space (WS) will
become vacant for sharing. It is strongly believed that the
devices with cognitive capability will be the prime contenders
for the dynamic spectrum access to TVWS. When developing
a TVWS system, three methods of sensing, beacons and Geo-
location combined with database are used to avoid interference
between TVWS devices and the primary TV band users. In
sensing, TVWS devices detect the presence of TV signals and
use the spectrum not used by the primary TV band users. In
systems using beacons, devices transmit when they receive a
beacon signal and the information of available channels. In our
project, Geo-location is used to allocate available spectrum at
a certain time in a given position. In Geo-location systems,
all devices including TV transmitters and TVWS devices will
register in a database and send the information of position,
power and so on to the database.
Furthermore, TVWS devices ideally should not cause inter-
ference to their adjacent devices. The challenge is managing
co-channel interference. For a large network with lots of
devices, allocating the channels among all devices to minimize
the total interference is an NP-complete problem. Briefly, this
means that globally optimal solutions to these problems cannot
be found because the computing time required to do so grows
exponentially with the problem size. Hence, heuristic methods
must be used, which find solutions that are close to optimal
in a tractable amount of time.
A distributed channel allocation was proposed in [1] based
on Simulated Annealing (SA). Authors developed a channel
allocation scheme to minimize the total interference of all
Access Points (AP) in WLAN. In [1], authors proposed a dis-
tributed SA to solve the dynamic channel allocation problem in
802.11b/g based HD-WLANs. When using SA, authors did not
mention the temperature initialization, the details of choosing
cooling schedule. And they did not give any other methods of
generating neighbor state.
Genetic Algorithm (GA) is a search heuristic that mimics
the process of natural evolution. This heuristic is routinely
used to generate useful solutions to optimization and search
problems. GAs belong to the larger class of Evolutionary
Algorithms (EA), which generates solutions to optimization
problems using techniques inspired by natural evolution, such
as inheritance, mutation, selection, and crossover. In [2, 3, 4,
5], GA is used to find a channel allocation from a search space
to satisfy some constraints. In [6], authors proposed a fully
distributed and self-managed algorithm. In [7], the channel
assignment problem is solved by a neural network algorithm.
In [8], authors proposed a hybrid algorithm that combines
GA and SA. The algorithm will trap in local minima, because
in the mutation step, authors allow the selected AP to choose
the channel used least among its neighboring APs. With such
a choice, the search strategy moves to the domain of local
search, and the mutation used to jump out the local minima
loses its original meaning.
SA is a powerful technique for finding near-optimal solu-
tions to NP-complete problem. However, SA relies on parame-
ters that have to be fixed before the execution of the algorithm.
It is usually very hard to choose appropriate parameters.
A good choice of the parameters depends on the particular
problem. Determining a good parameter setting often requires
the execution of lots of time-consuming experiments with the
aggravation that the best parameter setting for one problem
is of limited utility for any other problem. In this paper,
our contribution is to list all the parameters which involve
our own approach, to list most of classic methods of the
CROWNCOM 2012, June 18-20, Stockholm, Sweden
Copyright © 2012 ICST
DOI 10.4108/icst.crowncom.2012.248570