Mobile operators know they need to get their networks into shape for data services, but in many respects they are entering into unknown territory, reports Julian Bright.
Networks may not be as sexy as new mobile applications and services, but operators` service offerings will only ever be as good as the networks over which they are delivered. With the current low volumes of data traffic, however, the problem for operators is knowing what provisions in terms of capacity and quality need to be made in the network to support these new services, and how soon.
Analysts are predicting steady growth in data traffic over the next few years, at rates that suggest that capacity and quality issues will need to be addressed urgently. "Although initial take-up with be limited, gprs users will account for 24 per cent of all subscriptions by 2005," says Jonathan Bell, senior analyst for Europe at Pyramid Research. "That figure that will jump to 36 per cent of all mobile subscriptions by 2006. Operators will need to build capacity immediately to cover gprs networkrollout.
They are already feeling a crunch on voice capacity." Bell believes operators are currently only providing a few channels for gprs to get burst rates of 20-40 kbps. "In order to attract more users and increase bandwidth, I would anticipate that the average country operator will spend between $100-$200 million in GPRS capex over the next five years."
It`s a paradox, however, that even though operators would be delighted repeat the growth levels in new data services already experienced in sms, their networks would be ill-equipped to cope. "Most of the operators that we talk to in Europe claim that they don`t have capacity issues on their gsm networks," says Yosi Ben-Dov, chief executive of network optimisation specialist, Schema. "But as they move towards gprs, obviously they all foresee big capacity issues. Right now it`s a well-known secret in the wireless industry that gprs technology is such that if you have four or five users within the same coverage area of a cell, all the capacity will be gone."
However, with low user numbers and the loading on 2.5g networks still fairly light, operators haven`t really had to address these problems as yet, reports Denton Clutterbuck, business development manager for wireless network solutions at test and measurement specialist, Agilent. "What we`ve observed to date is most operators merely enabling gprs on their gsm networks, but not building gprs requirements." Clutterbuck argues that these networks are anyway still not "clean" enough from interference to carry high capacity data.
The problem is that at the moment operators are trying to plan for services that don`t exist, without knowledge of how, where or by whom they will be used. Assumptions that must be made at the network planning stage, with simulated user behaviour patterns, geographical distribution and concentration of traffic, and the dynamic mixing of multiple service types, remain unproven in a commercial environment.
STUCK IN TRAFFIC
A number of vendors are tackling the issue of network optimisation, especially in early build networks. Once again at this stage, gprs operators haven`t yet encountered many of the problems associated with the anticipated increases in data traffic, such as cell breathing. Schema, for example, believes it can reduce the need for extensive drive testing and the "trial and error" incremental approach adopted by most operators` optimisation groups or departments, and replace this with a one-step optimisation approach.
However, none of the existing data sources or methodologies is sufficient by itself to provide an understanding of what is happening in the network, argues Schema`s founder, Yuval Davidor. "You have to undertake a very complicated process of merging, integrating and cross referencing different data sources - some from operations, some from engineering, some from online information, and some offline information like measurements, prediction tools, switch statistics. Then it all has to be put together to bring the maximum capability to bear on knowing what is going on in the network."
A similar approach is adopted by network optimisation specialist, Actix, whose data analysis software processes performance data gathered from base stations, switches and other devices around the network. Chief technology officer Jeff Atkins believes carriers are beginning to tackle some important issues: "It`s interesting to watch especially with 3g looming, what`s going on with gprs," he remarks. "From an operational point of view, operators have backed into it. They have played with it and got it working, but are faced by the challenge of merging the two worlds - gsm and gprs." Atkins says that carriers are now ready to look at quality of service issues, such as how data and voice are interacting on their networks.
Brendan McDonagh, founder and chief executive of Aran Technologies, a Dublin-based provider of service assurance solutions, pulls no punches when it comes to quality: "There is no doubt in my mind that quality is a major issue. As these operators invest large amounts of money in services and content ... they are already aware that their brand will suffer and their data services offer will suffer, as will shareholder value, if these business priorities aren`t addressed."
The methods adopted by Aran Technologies add `intelligence` to traditional service assurance techniques, says the company. They represent essentially a pro-active approach, unlike the reactive situation that predominated in the voice world, explains Aran`s vice president for worldwide sales and marketing, Robert Blair.
"In next generation services the range of services used in, say, Glasgow will be different to those used in London," Blair explains. "So the operator will need to have the network configured differently. This cannot be fundamentally managed by the engineering resources available to the operator, they still have to keep their legacy voice networks going, hence they need a pro-active capability."
However, Blair acknowledges that operators are keen to tackle quality of service issues on their networks: "There is a very strong drive by the operators to understand how to get the right configuration. Operators are trying to get technical capability to meet their identified needs."
LEVELS OF SERVICE
The urgency with which operators need to tackle these problems will be dependent on the take up rate of new services. If, for example, multimedia messaging service over gprs takes off as hoped, traffic levels could rise rapidly. "I think it`s safe to say yes, operators want something like sms to come along, but if it happens it will be a huge shock," says Jeff Atkins. "They`ve really been focussing on just getting the stuff working, not thinking of the challenges of scaling gprs significantly."
Although the immediate challenge is to build capacity to handle the expected growth in data traffic, further down the line, particularly as operators move into 3g, provisioning according to quality of service is one approach that many have said they want to adopt. It will allow them to charge higher rates for premium services and differentiate their service portfolios.
However, this approach brings its own problems: "When networks get loaded, operators will have to think about who they want to charge for what, and how to maintain a high quality service for customers," says Clutterbuck.
Pyramid`s Bell agrees: "Quality of service will be a differentiator. Gprs marks the real revolution as we switch to packet-based networks. This means precedence, reliability and throughput can be sources of value."
As a spokesman for mobile operator mmO2 observed recently at the launch of the company`s Isle of Man 3g network trial, "If, for example, an operator is offering a guaranteed bit rate of 384 kbps to certain users, and `best effort` service to others, what happens when the guaranteed user wants access to the service? Does the operator degrade the best effort user to 120 kbps? Or maybe even 64 kbps?"
Maintaining service level agreements demands a detailed view of the network, adds Clutterbuck, and data throughput analysis tools can check performance of the network and help manage service levels. They are increasingly a part of operational support, with the ability to intelligently filter unnecessary alarms and only warn the operator when a serious problem such as service breakdown impacts service delivery.
Further into the future, Aran`s ultimate goal is the self-configuring network, says Brendan McDonagh. "We build up rules that allow us to determine what is the best configuration to address quality of service issues," he explains. "Our goal is to have a `click to fix` offering and down the road to do that automatically. But it will take a number of years. Operators are very cautious about letting software configure the network."
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