Analysis of Grade of Service of GSM

1
Analysis of Grade of Service of GSM

• S. O. AJOSE and A. M. ADEWALE

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OVERVIEW

• INTRODUCTION
• PURPOSE AND SCOPE OF WORK
• NETWORK PERFORMANCE / QUALITY OF SERVICE (QoS)
• MODELLING (THEORY)
• DATA COLLECTION
• SIMULATION
• CONCLUSION

3
INTRODUCTION

• GSM is the most popular second generation
  cellular system 1.
• The introduction of GSM has changed the
• landscape of telecommunication in the
• Country.
• 1 M. Boulmalf and S. Akhtar, Performance
  Evaluation of Operational GSMs Air- Interface
  (Um) College of Information Technology, UAE
  University.

4
Subscriber growth rate in Nigeria
2 Nigeria Communication Commission (NCC),
www.ncc.gov.org, Subscriber Data.
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PURPOSE AND SCOPE OF WORK

• The main purpose of this work is to
• identify the drawbacks to attain/achieve
• optimum network performance that have
• direct impact on user perceived quality.

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Network performance/Quality of service (QoS)

• Network performance is the indicator of
• the performance of a telecom network
• and of the degree to which the network
• conforms to the stipulated norms and
• standards specified by the regulator or
• any other agency designated for the
• same.

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Network performance/Quality of service (QoS)
(contd)

• Network Performance is the most important QoS
  parameter for measurement of quality of a Telecom
  Operator. Poor performance of a telecom network
  would induce customer complaints and faults,
  thereby leading to customer dissatisfaction
  towards the operator. The Network Performance
  parameter is further subdivided into the
  following
• Service Access Delay
• Call Set-up Success Rate
• Call Drop Ratio

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DATA COLLECTION

• The data had been collected from a real
  operative network. It was stored as Counters of
  different events in the network elements. The
  counters were stored every hour and then reset
  for the next cycle. The set of available
  measurements seems to consist of counter groups.
  Within a counter group, the counters are clearly
  connected while the counters from different
  groups are
• independent on each other. Therefore, the
  modeling problem is more easily solved by
  identifying a separate subsystem for each counter
  group separately.

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MODELLING
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MODELLING contd

• The system S1,1 describes the number of user
  perceived quality problems by summing the
  problems from four different categories, each
  focusing on different part of the transaction3.
  This model is of type I (see Table 4), in which
  the number of user perceived quality problems in
  the whole network is the output variable y(t) and
  the set of input variables xi(t) consist of
  number of blocked channel requests, the number of
  call setup failures, the number of calls dropped
  during transaction, and the number of failed
  handovers, each computed over the whole analyzed
  network.

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MODELLING contd

• The contribution of each
• problem type into the overall user
• perceived quality is described by the
• parameter ai, describing the percentage
• of the failures of type xi to the total
• number of failures y.

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S I M U L A T I O N

• The model developed in the last chapter
• has been simulated and would be analyzed to
  evaluate the contribution of the elements
  involved in call transaction to the grade of
  service.
• Some simulation samples are highlighted below.

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Chart of call attempts
14
Limited access to Network
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CONCLUSION

• As network operators are bringing new
  services to the delight of subscribers in the
  country, more attention has to be focused on
  improving the quality of service of their various
  services. The performance of the networks has to
  be addressed with a view of not only improving on
  their present facilities but also making room for
  further expansion to accommodate the teeming
  number of subscribers logging to the network on
  daily basis.

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CONCLUSION contd

• It is worthy to note that the major
• problems been deduced from this work
• are faulty hardwares, wrong orientation
• and tilting of antenna, bad coverage and
• speech quality, and congestion.