The threat that some smartphone operating systems and data applications could flood 3G networks with signaling traffic has been making headlines recently, but 4G networks look likely to up the ante on control plane issues.
Signaling has become a hot topic with operators, vendors, editors and bloggers as the growth of data on 3G has changed the nature of traffic on the network. Voice calls require a narrow control channel for setting up and maintaining a conversation, but some data applications can flood the narrow signaling channel by constantly pinging the network to maintain the session.
Light Reading Mobile has highlighted work from Nokia Siemens Networks that indicates Android and Research In Motion Ltd. (RIM)'s OS are "signaling bad boys" because they don't yet support a 3rd Generation Partnership Project (3GPP) standard that recognizes when a device is idle and reduces network chatter accordingly.
Other publications and blogs have been looking into how current and future networks and applications will handle signaling traffic:
The evolution of data traffic on 4G Long-Term Evolution (LTE) networks should be a concern, argues Richard Quinnell at Test and Measurement World. Repeated data connections on the signaling channel "can overload an LTE network's control plane long before straining the network's communications bandwidth if enough smartphone or tablet apps are placing frequent, low-traffic calls," he writes.
Industry people suggest the little-known Diameter protocol will help deal with the complexity of signaling traffic created by always-on data devices on LTE networks. "Diameter is the only signaling protocol that is capable of managing the constant flow of core network signaling in an environment that has become far more complex with many more network elements needed to fulfill the promises of 4G," writes Susan Becker, marketing manager at Traffix Systems on the snappily-titled Diameter Blog.
Certainly, Tekelec Inc. has started to get some traction with its commercial Diameter Signaling Router (DSR), recently winning an LTE deal with an unnamed "tier one operator" in the U.S. Tekelec says its DSR "provides up to 500,000 Diameter messages per second in a single frame." (See Tekelec Wins LTE Deal.)
Long-time telecoms guru Andy Seybold, meanwhile, reminds developers in a column at Fierce Mobile Content that dealing with the signaling problem shouldn't be all down to the operator. App creators have a responsibility to ensure that chatty apps don't flood the signaling plane too, he writes:
What should developers do to minimize the impact of their application on a network's signaling channel? The first thing is to look at other ways to update your customers' information. Can you do it with push technology that does not use the signaling channel? If you cannot, then look at how often the data really needs to be updated. Don't assume that you have infinite bandwidth, and understand that you are sharing it with many others. Write your applications accordingly.
Signaling traffic spikes can already be seen to have caused some serious problems on mobile networks. The "News and Views from Norway" website reports that in Norway this June, Telenor ASA experienced a major outage, likely because of signaling spikes when it rebooted some servers on the network.
Trace the growth of the signaling issue on LR Mobile below:
â€” Dan Jones, Site Editor, Light Reading Mobile