SQM for Mobile Networks 13FEB02

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					                                 White Paper


                    Service Quality Management
                                        For
                             Mobile Networks




                                     Author
                                    Ian Best


                       Director of Product Management




Comnitel Technologies – Confidential Property
No part of this Paper may be re-produced in any format without the author’s written
permission.
   Service Quality Management for Mobile Networks

Introduction
Service Assurance is fast becoming one of the biggest growth areas in the
OSS industry and a number of solutions are now emerging in the market
place to provide the technology to support the concept. But is a “one solution
fits all” proposition a viable answer to the problem?

This white paper looks at the specific problems of mobile service assurance
and examines some of the key issues involved with the successful
management of mobile data services.

Historically Network Operators have managed their networks using a number
of tools primarily aimed at monitoring the performance of the network
elements. Such tools include fault management systems at the element,
element management and network management levels. Often the events are
managed on the network element itself with no interaction with other
associated elements. Occasionally the events are collected by a network
level management system that correlates the individual events with other
events from associated equipment and in doing so provides some root cause
analysis. Most operators also use a network level performance management
system to analyse the behaviour of the network components and to some
extent the network itself. Much of this activity is a background analysis task
and is far from real time mainly due to the reporting intervals of the network
equipment.

Until recently, voice has been the predominant service and monitoring the
network has been a reasonable proxy for performance of this service.
However, with the emergence of a myriad of new data services, it is now
becoming recognised that management of this nature does not provide the
operator with a view on how the individual services are performing. Since it is
the service that the customer is paying for, it is the delivery of services to the
end customer that is now becoming the primary concern of the operator.

Arguably, managing network quality provides for a sound service delivery and,
therefore, managing individual services is unnecessary. However, this would
be true except for one critical point: networks do fail! Indeed, very few
networks are ever running completely problem-free. It is under these
circumstances that recognising the impact on individual services becomes
imperative in order to know which problem is affecting customers the most.




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It must also be noted that monitoring the health of the network components
does not necessarily provide visibility of the state of the applications that are
hosted on those components. It is, therefore, possible for the network to be
fully operational but for the service to be degraded due to a problem with the
service application.




The Need for New Management Techniques
The Service Quality Management Catalyst project sponsored by the
TeleManagement Forum was one of the first practical applications of the
principle of service quality management in a mobile network.

The project spent some considerable time analysing the data that was
available from the network of a leading UK mobile operator. This investigation
encompassed traditional Fault Management (FM) and Performance
Management (PM) data as well as clear codes from Call Detail Record (CDR)
data, and the various logs available from the network equipment.
Interestingly, of the 4,000 plus possible alarms that the network was capable
of generating, only four were found to give a definite indication of customer
impact. The most useful data source was found to be CDR data with PM
data: equipment logs also provided valuable information.

The underlining conclusion from the project was that the traditional method of
managing networks, through fault management, really gave little or no
indication of service quality as perceived by the customer. Critically, for the
Operator, it also gave no indication as to the impact on the revenue earning
capability of the network.

Service quality monitoring using multiple sources of data, however, did
provide an important insight on the impact on service delivery to the end user.



Mobile Networks Emphasise the Problem
There may be some argument that fault management in a fixed line network
can provide an adequate indication of service quality by applying the
monitoring at the Service Access Point (SAP). The argument is based on the
fact that the access points are fixed and can be, therefore, attributed to
dedicated network components. This argument, however, can only be applied




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to the most simple of service delivery models where there are single
components at each end of the service chain.




However, this approach, even in the fixed line world, is no longer as relevant
as soon as multiple resources are used to provide the SAP. At this point it
may not be possible to identify whether a single component failure is
customer-affecting as it may depend on the total service activity at that point
in time. Similarly, if the network provides multiple routing paths to connect the
two SAPs, there may be no way of quickly identifying whether a network
incident has impact on the service delivery to the end user.

In the mobile arena, the decision to implement Service Assurance becomes
much easier! While there may be dedicated resource allocated to the Service
Provider SAP, the access point for the end user will constantly change as the
user moves around the network. In reality, there is also likely to be multiple
access points for the Service Provider. For example, in a GPRS network,
routing for a Service Access Point Name (APN) will almost certainly be via
multiple Gateway GPRS Support Nodes (GGSN) and the end user access
may be from any Serving GPRS Support Node (SGSN) in the network. Trying
to manage the service delivery quality by monitoring the alarms from the
network is, therefore, obviously inadequate.




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There are a number of other aspects of the mobile network that make the
management of service quality more complex. While managing the quality
through the IP network may be fundamentally the same as for any IP based
service, an IP connection that utilises a mobile network requires specialised
knowledge of the mobile domain.

Taking a typical GPRS network as an example, there are a number of
components that are unique:




In the fixed network, the bandwidth to the end users’ terminal equipment (TE)
may be fairly predictable. In the GPRS network, however, it is very much
more variable (even when ignoring the variations due to radio wave
propagation). Higher bandwidths in GPRS are achieved by using multiple
downlink channels (between the Radio Access Network [RAN] and the TE).
The bandwidth allocated for a specific connection is, therefore, dependent on
the cell loading at any particular time. This may even vary during the duration
of the connection as the number of users on the cell, and the applications that
they are using, changes. The bandwidth availability may also vary as the user
moves from one cell to another. As the bandwidth allocation is a factor to
consider when measuring the service quality that a customer experiences, the
service monitor must consider the requested bandwidth versus the actual
bandwidth throughout the transmission time and wherever the connection
exists within the network.




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There are a number of additional elements in the GPRS network that also
need to be considered when measuring the end-to-end service quality. The
GPRS core elements will obviously introduce additional latency into the
packet transfer time between the user and the service origin and this mus t be
included in the total end-to-end latency. The SGSN and GGSN interface uses
the GPRS Tunnelling Protocol (GTP) and this must also be considered when
measuring the customer experience. The GSN switches are essentially
Routers, and these will need to be configured so that channel priority settings
do not result in isolation of sections of the network under high load or
connection failure conditions. A good SLM tool will be able to recognise such
failures and dynamically re-allocate channel priorities to prevent this isolation
occurring. The initial connection time delay must include delays within the
SGSN and HLR etc. All of this points to a very specific application of the
basic principles of monitoring when managing service quality in a mobile
network.

As already noted, CDR information is a very valuable information source for
measuring the customer experience. GPRS introduces two new sources of
CDR in the SGSN and GGSN. Mobile service management solutions must be
capable of extracting this information if an accurate measure is to be
achieved.

It may be possible to ‘hide’ these mobile specific implications by the use of
probes within the IP domain and thus provide an approximation of the
customers’ perception of service quality. For this to be entirely true it would
be necessary for such probes to interact in some way with the TE and the
future may provide solutions of this nature. However, understanding the
quality of service being delivered is only one part of the problem. What if the
quality is degraded? Providing the operator with an indication that there is a
problem with a service is of limited use if there is no indication as to the
source of that problem, or of the impact of that problem on the customer and
the operator. Remember: one measurement of customer satisfaction is the
time to correct a problem!

It is, therefore, important to achieve end -to-end service monitoring through the
aggregation of a number of more granular parameters. By applying quality
objectives against each of these parameters, it is possible to identify the
service component(s) that is causing the degradation and thus assist the
operator with the corrective action. This will improve revenue and increase
customer satisfaction.




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Looking at the process of recovering a degraded or failed service we can
simplistically break it down into four phases:




Through accurate service monitoring the operator will be able to reduce the
time taken for each phase:
   ?? Detect – detect degradation of service quality in real time rather than
       offline analysis of alarm and performance data etc.
   ?? Analyse – through a granular approach to monitor services, improve
       analysis time by presenting the engineer with data identifying the failing
       service component.
   ?? Fix – focus resources on fixing the problems that are affecting the
       customer (and revenue) rather than non-service affecting problems.
   ?? Recover – drive faster recovery of the revenue stream (this is the
       subject of this White Paper – ‘Bridging the Gap between Network and
       Customer’)

The overall effect is a faster return to revenue generation from the Operators
perspective, and an improved customer experience.




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Summary
If mobile operators are to maximise the return on investment from service
quality monitoring systems, the solutions must provide accurate information
about the services delivered to customers. Assistance with service recovery
during failure conditions, and help in prioritising such activity on the basis of
revenue and customer service impact are essential.

It is clear that the maximum benefit to the mobile operator can only be
achieved from Service Level Management solutions that are developed on the
general principles of service monitoring. Equally important are an underlying
knowledge of the service components in the mobile specific space, coupled
with a knowledge of the contractual commitments that the operator is making
to their customers.

We must, however, recognise that the RAN and GPRS core cannot be
managed in isolation of the IP network and the service monitoring solution
must be equally capable of accurate and granular monitoring of these service
components.

Such solutions will either develop through a broadening of knowledge within
the OSS solution provider or through partnerships between IP solution
vendors and their counterparts in the Mobile arena.




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About the Author
Ian Best, Director of Product Management, has over 30 years of experience in
the telecommunications industry and is a recognised industry specialist in
Operational Support Systems (OSS), specifically in Service Management for
Mobile service providers. Prior to his current position at Comnitel, Ian was a
technical specialist at UK Mobile Operator, Orange where he was responsible
for their service management strategy. While with Orange, Ian played a key
role in defining their strategy for managing 2.5G and 3G services. Coming
from an operations background Ian is now in a position to have the
opportunity to deliver the solutions capable of meeting the industry’s
requirements, delivering a new breed of OSS solutions that will enable
customers to differentiate themselves in the ever-increasing competitive
market. Ian is responsible for the direction and roadmap strategy for
Comnitel's mSure™ product suite.

Ian also plays an active part in a number of industry projects (Wireless
Service Management) as a member of the TeleManagement Forum. This
further enhances Comnitel's growing reputation as the thought leader in
mobile service assurance.


About Comnitel Technologies
Comnitel Technologies is the leading supplier of mobile service assurance
solutions to global mobile telecom service providers, with offices in Cork,
Ireland and Cambridge, UK. The company's Research and Product
Development centre, located at its Cork headquarters, is exclusively
responsible for developing service assurance solutions for mobile networks.
The commercial division of the company is based in Cambridge, UK.

Comnitel is unique in that its entire organisation is drawn from the mobile
industry, from all the leading equipment vendors such as Ericsson, Motorola,
Nokia and Lucent, and major international Mobile operators. In particular, the
company's senior architects had previously formed the backbone of design
teams that had developed General Packet Radio Service (GPRS)
infrastructure for a number of leading equipment vendors. Combined with a
strong IP expertise, this has provided a unique understanding of the complex
issues of managing the combined wireless and IP infrastructure of 2.5G and
3G networks.




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Comnitel Technologies is funded for success with an impressive group of
international investors. The executive management is drawn from the leading
players in the mobile industry.

Comnitel's founders, Declan Fox and Kieran Moynihan, have many years
combined experience managing and developing                 leading    edge
telecommunications products. The non-executive board includes experienced
executives drawn from the wider communications industry. These include the
European chairman of a $30 billion US based communications company, the
CEO of the leading European financial venture capital fund, and other
seasoned professional veterans from the telecom and financial sectors.

For more information please contact info@comnitel.com




                             End of Document




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