June 2012

The 4G Challenge that Networking Users Now Face
By Daniel Barry, VP , Napatech

One of the biggest technical challenges facing the networking industry today is the demands that the next generation of cellular communications known as 4G (for Fourth Generation) will place on the network backhaul and communications networks generally.

4G better known as Long Term Evolution by those in the know is a revolution in terms of data speeds, but is actually a natural upgrade for existing 2G and 3G cellular networks, achieving downstream speeds of an astonishing 300 Mbps and uplink speeds of 75 Mbps.

And just to make life interesting, because LTE is designed as the name implies as an evolutionary standard, even higher speeds are made possible through the use of LTE Advanced (LTE-A) technology.

Early tests of LTE-A suggest that mobile data speeds of 1 Gbps (yes, a gibigabit per second) downstream are going to be the norm when the technology arrives commercially in the latter half of the decade.

Achieving these kinds of speeds on a mobile basis is not actually that difficult because of the cellular/wireless technology involved, but the real fun and games from a networking perspective comes when all of this data needs to be backhauled across the wireline network and interconnected with the Internet and other mobile services.

“But hey, it’s mainly voice communications we’re talking here and voice calls consume only a smidgen of networking bandwidth, so what’s the big deal?”

This might have been true in the past, but figures released late last year by Three the smallest of the UK’s five main cellcos show that 97 per cent of its mobile network usage in the UK is data-based (http://bit.ly/xZv8B8).

And if you need confirmation of how much bandwidth is being consumed by the cellcos, take a look around you when you’re next on the train, and you’ll almost certainly see a lot of people surfing, emailing and interacting and all using their smartphone or laptop computers.
This surge in cellular networking usage will need four main pillars of support: excellent network monitoring, testing, security, and optimization.

Since 4G mobile networks like LTE are entirely packet based (rather than circuit-switched like 2G and 3G), there is a greater need to monitor mobile networks in real-time to understand where traffic is coming from, where it is going, which applications are being used, and by whom.

This information can be used for efficient planning and anticipating network problems before they occur. But, even more importantly, this information can provide the basis for making more intelligent decisions on how to offer services to customers and under what terms. Since packet networks are shared, one user can potentially hijack bandwidth, starving others in the process. So, while you might have a 1 Gbps download capacity, you are not able to download as that bandwidth has already been taken upstream.

One of the potential areas of congestion in mobile networks is the increase in signalling traffic. Each time a service is used, signalling is sent back and forth to help set up and support the service. With the multitude of apps on smartphones today, there is a real danger of a signalling explosion on mobile networks.

Excellent network testing based on protocol analysis and synchronized traffic generation helps planners to ensure that these scenarios are taken into account. Protocol analyzers use probe technology to remotely monitor critical points in the network, analyzing and collecting information on signalling traffic amongst other things. This allows operators to monitor performance in real-time.

Synchronized traffic generation allows multiple time-synchronized load testing systems to be located at various geographic locations, simulating a large number of mobile devices. Since the systems are synchronized with nanosecond precision, it is possible to load the network with data from multiple locations at exactly the same time. This is an invaluable tool in simulating potential “network-crashing” events.

Optimum security for these IP transmissions will also be required, as the sheer volume of data flowing across cellular network backhaul networks will make the backhaul networks a key target for cybercriminals remember that a growing number of mobile broadband users will be accessing their online bank accounts and making transactions with their mobile phone.

The final networking pillar required will be excellent network optimization, which will help the cellcos — and their national network partners extract optimum bandwidth out of their finite network resources.

Indeed, one can take this one step further and call it service optimization, as the main goal is to ensure that mobile users can access the services they need when they need them, with a quality of service for which they are willing to pay. Optimizing the network is thus a part of the service assurance process, but the information gathered by network optimization nodes, such as Deep Packet Inspection probes and Policy Enforcement Servers can be used by cellcos to offer services which are more in tune with subscriber needs, such as ensuring maximum performance for Facebook® or gaming or providing higher bandwidth services at different times of the day.

The common theme for these 4 pillars is the need for a network monitoring and analysis infrastructure to complement the communications infrastructure of 4G mobile networks. To ensure that available bandwidth and resources are used optimally, especially in the face of explosive data growth, it is essential that the right network monitoring infrastructure based on independent deep packet capture probes is established.

This approach is already widely used for network monitoring, testing, security and optimization of Ethernet and IP networks and can be readily applied to 4G mobile networks.

Running a mobile network without an effective network monitoring and analysis infrastructure is like driving a sports car at night with the lights off. As long as the road is straight, no problem. But, when the road curves...

For more information, visit www.napatech.com.

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