27 March 2012
Helping mobile operators to help their customers
According to mobile telecom consultancy Unwired Insight, March 2012 saw data services overtake voice as the main source of revenue for the UK's mobile operators.
But data services present operators with challenges. Operators want to boost the profitability of data services and manage data traffic that is growing rapidly. They also want to ensure that subscribers are satisfied with their services; it is more costly to acquire new subscribers than to keep them.
Currently, policy – which enacts operator defined rules to address network congestion, service quality and how operators offer and charge for services – is implemented in the network. However, UK technology consultancy Roke Manor Research has developed a software application – a policy engine – that sits on the handset. It claims that, by placing the policy engine, dubbed SmartSwitch, on the handset, new service and networking capabilities become possible. "From a device perspective, policy is fantastic because the device has a lot of knowledge and measurements about its environment," said Ben Toner, business sector consultant at Roke Manor Research.
To improve profitability, operators want to be smarter with their service offering and in their interactions with customers. "Most operators are talking about service tiers that a user pays for – gold, silver or bronze – and which have a real time quality metric," said Toner.
Operators want to enable users to hop temporarily between service tiers, depending on their requirements. For example, a bronze tier may be fine for emails, but less so for video. A user may be willing to upgrade to a higher tier in order to view a sporting event in high quality before reverting to their original tier.
Operators also want to inform users of such options, especially as their service plans near their end. "You then don't think of the network as offering a low quality service," Toner noted. "Instead, you are appraised that the plan you have is giving the particular level of performance, but that the network can provide more."
By not giving everyone the same service quality, operators can better predict the level of service needed and dimension their networks more accurately. That saves operator spend on network infrastructure, says Toner.
But to offer such data service enhancements, operators must first understand the data types used in their networks and be able to charge for them. Data classification is done using deep packet inspection (DPI), equipment in the network that inspects packet headers to classify the different data consumed by handsets.
DPI has been proposed to manage network congestion by limiting identified traffic types, but this becomes complicated. DPI may be able to block video traffic, but Toner wondered what would happen if a user who is not entitled to video watches a video clip via their FaceBook application? The last thing they would expect is for their level of internet access to curtail their FaceBook features.
Another shortfall of DPI is that it resides in the network and therefore cannot solve all congestion; in fact, the handset can cause congestion that overwhelms the cellular air interface. "By the time it reaches the network, congestion has already happened," said Toner, who cited a network outage suffered in January by Japanese mobile operator NTT Docomo.
"NTT Docomo's network went down for four and a half hours because of one Android application," he pointed out. The application created excessive signalling traffic that overwhelmed the network. The outage has proved costly and, in response, NTT Docomo has pledged ¥50billion (£388million) of additional investment to bolster its network.
Roke Manor's SoftSwitch policy engine was designed to tackle issues of handover between cellular and Wi-Fi networks, but has been enhanced to support policy. The core network sends descriptive rules to the handset which enacts intelligent data management decisions based on conditions and measurements it sees, said Toner.
An operator can exploit handset based policy for real time messaging by sending the user new policies – for example, when the core network notes that a user has consumed 90% of their plan. "The core pushes a message to your device, right over the top of any video you may be watching," said Toner. The messaging is two way, taking the user to the operator's portal to manage their data plan.
The policy engine can be used to address signalling congestion using a firewall on the device. "It is possible to block what we call a rogue application," said Toner. For those rare situations where an application's signalling threatens to overwhelm the network, an operator can identify the application using DPI and, by sending a policy update, stop the application's data getting onto the network.
The engine also manages network connections. For example someone living in the centre of London, where free Wi-Fi is being rolled out, may prefer to stay on their own Wi-Fi access point, especially if the free service is congested. "This requires user interaction," says Toner. The handset policy interface will trigger a message to show when free Wi-Fi is available. The user then decides whether to connect and even whether they want to see the message again at that location (see box).
Because SmartSwitch sits on the handset as a software application, operators could offer it via their 'app store'. "A very good reason why you'd want to keep it as an app is to hit all the devices out there," said Toner.
In handset operating systems, such as Android, much of the information a device sees is readily accessible. Data such as Wi-Fi and cellular network signal levels, whether Wi-Fi is on and the remaining battery life can all be queried.
SmartSwitch runs continually, but is designed to limit the processing load it places on the handset. Certain policy data used by SmartSwitch can be prioritised; for example, location or signal strength. This way, SmartSwitch does not need to access all device measurements.
Android can also send wake up messages if, for example, the handset location changes. "We do have some periodic scans," said Toner. But these are aligned with the operating system's scans. "For very little extra resource, we can check to make sure we are not missing anything," he concluded.
Roke Manor says SmartSwitch is 'production worthy' and is being demonstrated to operators and policy vendors. Roke has also signed partnership agreements with policy vendors that want such a handset capability.
Policy in action
A policy engine works using an operator-written file that defines conditions and actions. An example rule and action are: 'IF you are in that location AND that app is active AND the battery life is below a certain level, THEN select Wi-Fi and autheticate it with this password'.
The policy uses an agent technology that evaluates the best overall decision if more than one rule is evaluated.
For example, there may be a rule not to enable Wi-Fi while a certain application is running, such as a file download, so the download is not interrupted, much to the annoyance of the user. There may also be a second rule that states that on entering a location, always connect to Wi-Fi. If both rules are triggered, clearly the first rule takes precedence.
Chemring Technology Solutions
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