Everyone is busily preparing for GSMA’s Mobile World Congress in Barcelona next week, the theme for which is “The Mobile Horizon”. No doubt many operator discussions will focus on what’s next in LTE networks, and there most certainly will be an endless stream of “cloud” announcements.

These are exciting developments for the industry that hold great promise for better overall delivery (leading to improved customer satisfaction) at a reduced cost, but there is a cautionary tale in the background: you can’t scale your network through LTE upgrades or ‘cloud’ virtualization alone; your signaling environment has to be equally robust.

To understand this better, let’s unpack the market and network dynamics that got us to this point. As consumers rapidly adopt mobile devices and applications as part of their immersion into a digital lifestyle, the demand for bandwidth becomes outsized, leading to traffic chokepoints, even on important traffic. Soon everyone is unhappy.

In an effort to remedy this problem, operators have adopted strategies such as WiFi offload and creative offer packaging and pricing. These are good “holding actions,” but are not sufficient in the long term. Operators know this and are deploying LTE network capabilities in the hopes of being able to better serve these same demanding consumers with a more cost-effective (and eventually all-IP) network.

Finally, there is a great flurry of data center activity to put everything in a cloud environment for on-demand access to resources.

Likewise, software-defined networking (SDN) holds promise as a means to virtualize network resources in ways that will serve these varying levels of demand in the most dynamic, low-cost ways.

All of these are useful tactics, but they don’t really get the whole job done.

Recall that at the highest levels, SDN separates the control plane, i.e., the orchestration of resource allocation in the data center from the “data plane”. Inside the data plane, of course, resides the actual end-user payload. But a less-often discussed component – Diameter signaling –allows the great variety of servers, gateways and other network elements to set up sessions, authorize users and enable charging for the newest and potentially most profitable services.

Cloud virtualization certainly allows the two SDN planes to operate and scale in balanced, complementary ways so that one only spends what is needed to grow the network, but still serves user demand . At the same time, signaling must be even more robust.

According to the Tekelec LTE Diameter Signaling Index™, while data demand is growing at unprecedented rates, the signaling associated with this demand is growing three times faster!

Without an adequate signaling infrastructure based on a centralized, core Diameter signaling architecture, the network continues to be constrained by the communication path between elements such as gateways, charging systems and policy engines.

So while you’re noshing on tapas at the Fira Gran Via next week, consider not just your LTE network element and cloud needs, but the Diameter signaling requirements that actually ensure these investments deliver on their promise.

Downtown DC has braced for the arrival of up to 800,000 people, who will observe the 57th U.S. Presidential inauguration today. The event will be tweeted, shared and recorded on video by the assembled crowds, some of whom will be using 4G services and applications on their smartphones.

Besides the additional data traffic surge, Tekelec expects this event to generate increased Diameter signaling traffic, thanks to an increased density of LTE device users attending the ceremonies. In fact, the 57th Inauguration is sure to be very different from the 56th in terms of technology: four years ago, smartphones only had approximately an 11 percent market penetration – and BlackBerrys outnumbered iPhones two to one.

Additionally, LTE was not yet in service anywhere in the world.

Now, more than 55 percent of Americans own a phone that is capable of video streaming or Internet connectivity – a total of more than 100 million Smartphones. Add to the mix a new, dedicated free Inauguration app with live streaming (Inauguration 2013), and it’s easy to see how mobile data and subsequent Diameter signaling traffic will surge.

The density of LTE-enabled devices means that 4G coverage will be seriously tested during periods of peak usage, thus forcing subscribers onto 3G and Wi-Fi networks. Also, attendees’ mobility in and out of coverage areas may cause subscribers to switch from LTE to 3G networks, and back again. The result on the core network will be periodic spikes in Diameter signaling traffic.

It will be interesting to see how operators fare once users start comparing what they expect from their devices and mobile network providers, and what actually ends up taking place to either enhance or mitigate the Inauguration experience.

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Today we released our Diameter Signaling Index – a first-of-its-kind “guide” designed to help architects, engineers and marketers calculate the impact of devices and services on network signaling traffic.

It’s perfectly timed, as the iPhone 5 will be a prime example of the multi-session nature of new devices and the multi-tasking that will ensue for each subscriber. The consequent surge in Diameter traffic will require unprecedented levels of orchestration and communication among user to devices, cell towers, policy servers, charging systems, and subscriber databases and gateways.
As indicated in the report (which took a conservative road in its assumptions), there will be 47 million Diameter messages per second by 2016, representing a compound annual growth rate (CAGR) of 252% between 2011 and 2016.

The iPhone reflects the type of sophistication that will trigger more use cases around policy, which will in turn trigger more Diameter signaling. Mobility management functions and roaming will all have substantial impact.
So what does it all mean for operators, who obviously know what’s coming and have been building Diameter signaling strategies into their planning?

It means that what used to be addressed with a mesh approach to Diameter must now be addressed with more of a centralized approach. A centralized Diameter signaling architecture will be needed to effectively route, measure and monitor Diameter traffic so that signaling storms are held at bay, and so that the customer experience is optimized rather than compromised.

And since authentication will be invoked each time someone powers on an LTE device, or every time someone activates a new device (as with the 10 million iPhones forecasted to be sold this month), there could be as many as 60 million authentication messages generated by that event alone.

So, just as the original iPhone changed phone usage habits, so too will the LTE iPhone have an impact on LTE networks. New usage profiles and patterns combined with tiered service plans and the associated policy and charging information will equal A LOT of Diameter traffic. Charging for example could represent as many as 6 Diameter messages per session (depending on the type of session, billing arrangements, and numerous other factors, 6 is conservative).

New business models such as sponsored traffic and advertising also will require Diameter interactions, which means we’ll see more centralization of Diameter architecture to accommodate the evolution to LTE – on the iPhone and other devices.

With the Olympic Games just around the corner, network engineers everywhere are asking the same question: ‘How big an impact will the Olympics have on wireless networks?’ The Olympics can serve as a microcosm of analogies to a bigger issue – the impact of data surges on Diameter signaling, especially where LTE coverage is available.

The Olympics pose an opportunity for service providers to monitor Diameter signaling traffic and analyze the trends for future engineering. In doing so, they have many points to consider:

For one, it will be interesting to see how the cellular networks perform in London. Though the packet network will be upgraded to support higher data rates, the signaling core will remain SS7, as LTE will not be implemented in time for the Games.

Two, the devices and the savviness around their use have only improved since the last Olympics in Beijing, so social media and mobile devices will be the primary media over which events will be viewed and information shared. Video usage will be off the charts in comparison to what was possible in China, where the first “digital” Olympics took place (albeit on far fewer channels than are available today). There’s no question the London Games will generate unprecedented amounts of video content via official and not-so-official channels, such as Olympic Committee YouTube channels and related Facebook, Twitter and other social media channels. All will see significant increases in their traffic as viewers in different countries elect to watch through their iPads and Smartphones.

NBC alone is expected to deliver 5,535 hours of programming, with HD programming available through broadcast channels. Additionally, NBC (and other broadcasters like the BBC) will provide live streams through various web sites and social media. While this may not have a direct impact on London mobile networks, there may be residual impacts on home networks where LTE is available, as social media connections will inevitably increase Diameter signaling –especially where connections are left on all day, and if policy is implemented to assure certain quality levels or to control congestion.

Another interesting point to ponder is the level of personalization that will emerge in these Olympics. For example, NBC will allow viewers to select what view of an event they want (i.e., what apparatus in a gymnastics event they want to see). That ability may generate a significant amount of video streams and hence a lot more signaling (albeit Diameter signaling as opposed to SS7 signaling).

In addition to watching the impact of actual video consumption, operators should watch closely the impact of WiFi, as roamers will have about 100,000 hotspots throughout London with which to alleviate roaming fees they’d otherwise incur on the mobile network.

In all, London will strive to provide 4 times the capacity than was possible in Beijing. With so many visitors and professionals covering the events (21,000 reporters converging on the city to cover the Games), every Gigabyte of capacity will count.

Not only should mobile operators consider the impact on London’s networks, but also the impact on their own networks, as fans not able to travel to London will watch their favorite athletes through the numerous online channels being made available to them.

With millions of Smartphones and tablets sold in the last several years (especially iPads and iPhones), expect a huge increase not only in data traffic but in signaling traffic as well.

As stated earlier, Diameter will be affected anywhere 3G or LTE is deployed. It’s just not clear yet how significantly. We suspect there are enough subscribers on LTE networks today to have an impact on any service provider’s network.

With so many variables to Diameter traffic engineering, it is impossible to put a number on the amount of Diameter traffic we will see just by evaluating data. Suffice it to say, however, there will be significant impacts on signaling as a whole, and where policy is implemented in 3G and LTE networks, that impact will be much greater.

Ever wonder what Lily Tomlin was doing when she would say “one ringy dinghy, two ringy dinghy”? Or how about Sarah in Mayberry RFD when Andy would pick up the phone, turn the crank a few times, and ask her to connect him to Aunt Bea? These are all examples of signaling being used to connect calls in the days before electronic switching. When you wanted to make a call, you turned a crank on the side of the phone, which then triggered “signaling” in the form of a light illuminating and a bell ringing on a switchboard.

The operator would then ask a series of questions so she knew how to connect your call (signaling again), after which she would manually plug a cord into a jack on the switchboard, completing the circuit to the destination, or to another operator in another city.

Signaling has changed drastically through the years, with everything involved now fully automated. Signaling allows the various elements within a network to communicate with each other regarding a specific connection. But nowadays, signaling takes many forms, depending on its purpose. There is signaling between a mobile device and the cell tower. There is signaling between the cell tower and the core network. And there is signaling within the core of the network. Regardless of its purpose, signaling up to now has been nothing more than pure overhead, contributing little to service provider revenue.

Though signaling has taken many forms over the years, the industry is now making a concerted effort to consolidate technologies and reduce the number of signaling methods used in networks to just two: Session Initiation Protocol (SIP) for connecting voice and video, and Diameter protocol for authorizing and authenticating subscribers and their devices.

Not only is Diameter used to access subscriber databases authorizing network access, but it also is used for charging as well. Most importantly, Diameter is used by network elements to communicate with the Policy and Charging Rules Function (PCRF).

It is the PCRF in the Evolved Packet Core (EPC) that allows service providers to personalize services they deliver to their subscribers, whether tiered service plans, parental controls or others. The role of policy in the network continues to grow as service providers get more and more creative with the rules they can generate to control the traffic in their networks and define new services.

The PCRF not only contributes to the bottom line on the balance sheet, but it generates new revenue streams for service providers such as mobile advertising and over-the-top (OTT) application subsidies.

Never before has one function in the network represented so many new opportunities for service providers, which are literally redefining the role that they play in the mobile ecosystem. They can now offer to their subscribers more intelligent choices tailored to their lifestyles, while also engaging new partners previously seen as competitors for the purpose of creating more compelling services.

OTT players such as Google, Facebook, and YouTube depend heavily on the network to reach their subscribers, but until now have contributed little to nothing back to the service providers as compensation for the network costs. But that can change as OTT players come to realize the value of becoming partners. As that happens, signaling will continue to move to the spotlight as a revenue generator rather than a pure cost of doing business.

As that happens, Diameter will be the signaling protocol that makes monetization of OTT services possible, and it might possibly be the one technology that will change the face of service provider business models forever.

In February 2012, Infonetics Research published its inaugural Diameter Signaling Control worldwide and regional market size and forecasts report, in which we reported worldwide sales totaled $8.6M in CY11. The Diameter signaling controller market is in its infancy; as we predicted, a growing number of new products have launched in the past three months, and we expect more through 2012. As with all new markets, Diameter signaling controllers will expand functionality to meet operator requirements and use cases. We forecast revenue to grow at a 106.2% CAGR through CY16, resulting in $321.3M in revenue that year.

As mobile operators migrate to all-IP networks (access to core), signaling standards are migrating from SS7 to Diameter. At its core, Diameter enables the exchange of policy information within and between network operators. Diameter has also been developed as the foundation for authentication, authorization, and accounting (AAA) functions in IP-based networks.

Diameter signaling controllers provides centralized routing, traffic management, and load balancing among Diameter and non-Diameter elements within IMS and mobile broadband networks. It also supports protocol mediation and interworking functions between carrier networks. A fully loaded Diameter signaling controller will encompass the Diameter agents, DRA, DEA, and load balancing.

The move to all-IP mobile networks is being driven by LTE, and Infonetics forecasts that the number of LTE subscribers worldwide will grow from 9.2M in CY11 to 130.2M in CY15. The escalation of subscriber growth and the amount of signaling traffic these subscribers will generate is at the heart of our Diameter signaling controller forecast model.

As LTE networks are deployed and begin to grow, a key challenge is scaling the signaling and control plane due to the increasing amount of Diameter messages passing among network elements. Several global operators have experienced significant signaling storms in their LTE networks that in some cases have resulted in network outages. The storms have been caused by growing usage of the networks, but also by architectures that allow Diameter signaling to be dealt with on a peer-to-peer basis.

The increased use of mobile broadband networks is driving the growth of Diameter signaling within and between operators. This signaling traffic in turn has hastened the need for centralized controllers that can help manage the traffic in a more efficient and scalable manner. There are a number of key drivers to consider when evaluating the future growth of Diameter signaling traffic that will require signaling controllers:

• The continued rise in smartphone adoption as prices continue to drop due to strong competition and broad availability from high-end to low-end devices
• The availability of advanced 3G and LTE services such as tiered pricing and shared data plans, which require more frequent exchanges of policy and charging information
• The increase in the number of 3G and LTE network elements, particularly related to policy and control (e.g., PCRF, HSS, OCS), that must communicate with each other
• Roaming in LTE networks and between LTE and 3G networks, as well as subscribers moving between 3GPP (LTE/HSPA) and non-3GPP networks such as WiFi

A number of vendors are clamoring to play a role in this emerging market. We expect to see Diameter signaling controllers from at least 15 vendors by the end of 2012. Not all vendors will be successful, as the market cannot support that many, but we expect the competition to spur further innovation.

Today Tekelec is the front-runner in Diameter signaling control, with a strong revenue lead in 2011, helped by key wins in North America, including Verizon Wireless for its 3G and LTE networks and MetroPCS. With its heritage in SS7 and SIGTRAN, Tekelec has been an early mover in the Diameter signaling controller space and is well positioned for the future. In our February report, we asserted that Tekelec’s ability to draw upon its installed base of legacy customers will make it a formidable competitor. Since then, Tekelec has continued to increase its customer base for its Diameter Signaling Router (DSR), announcing 15 new customers across all regions, which confirms our statement. This brings their customer base to 19 for the DSR, totaling 1.8 million messages per second across a variety of use cases including interconnection for roaming, scaling policy deployments, core routing for LTE and IMS networks, and providing subscriber locator function in an LTE architecture.

Diane Myers

Principal Analyst, VoIP and IMS

diane@infonetics.com

CTO Doug Suriano explains how the new iPad will create signaling challenges for mobile operators in a recent Forbes article:

The iPad 3 supports HD video, over-the-top services such as Facebook and Twitter, as well as a wide variety of data-heavy consumer and business applications. However, the rise in mobile data traffic will not be operators’ primary problem. They have been aggressively addressing data capacity for years with strategies such as migration to 3G and LTE, policy control and offloading traffic to Wi-Fi.

With LTE, operators will need to handle network signaling messages. Signaling involves the underlying communications that enable charging, billing, user authentication and authorization. These essential messages support data activity over 3G and LTE networks. The impact of network signaling, however, has gone largely unreported.

Click here to read the entire article.

CTO Doug Suriano discusses how mobile data will spur innovations in 2012 – especially in terms of pricing models – in an article for RCR Wireless. He predicts that this year will see advancements in personalized plans and cloud services, as well as a major rise in signaling traffic.

According to Suriano:

As mobile data matures in developed markets, we expect several significant evolutions in 2012. The biggest for subscribers will be pricing plan innovations, providing new personalized service and cost options. In addition, we forecast rapid cloud service adoption, new content business models and new device segmentation.

The full article can be found here.

By Matt McCann, Principal Architect

The Diameter protocol is widely used in 3G, IMS and LTE architectures to transport policy, charging, authentication and mobility management messages – traffic that will rapidly rise as mobile data usage increases.

To best manage the growth of Diameter traffic, operators are examining how to create a separate Diameter signaling infrastructure at the network core. The goal is to facilitate signaling between network elements, eliminating a mesh-like architecture of direct connections between endpoints such as mobility management entities (MMEs) and home subscriber servers (HSSs). This would relieve endpoints of handling all session-related tasks such as routing, load balancing, congestion control and failover management.

Initially, implementing an IMS or LTE network without a signaling core may be sufficient, but as traffic levels grow, the lack of a capable signaling infrastructure poses a number of challenges, including:

• Scalability: Each endpoint must maintain a separate SCTP association with each of its Diameter peers as well as the status of each, placing a heavy burden on the endpoints as the number of nodes grows.
• Congestion control: Diameter lacks the well-defined congestion control mechanisms found in other protocols such as SS7.
• Protocol mediation: Vendors are likely to use their own variants of the Diameter protocol based on how they believe a specific interface should be implemented. This implementation can vary slightly from those of another vendor, creating potential interworking issues when multi-vendor equipment is combined in one network, a common approach for operators that take a best-of-breed approach.
• Network interconnect: A fully meshed network is completely unworkable when dealing with connections to other networks because there is no central interconnect point. This also exposes the operator’s network topology to other operators and can lead to security breaches.
• Interoperability testing (IOT): Protocol interworking becomes unmanageable as the number of devices supplied by multiple vendors increases. With no separate signaling or session framework, IOTs must be performed at every existing node when a new node or software load is placed in service.
• Support for both SCTP- and transmission control protocol (TCP)-based implementations: SCTP-based elements cannot communicate with TCP-based elements unless they are upgraded or all of the elements support both protocol stacks.
• Subscriber to HSS mapping: When there are multiple HSSs in the network, subscribers may be homed on different HSSs. Therefore, there must be some function in the network that maps subscriber identities to HSSs.
• Policy and charging rules function (PCRF) binding: When networks require multiple PCRFs, operators must have a way to ensure that all messages and sessions associated with a particular user are processed by the same PCRF.

Centralizing Diameter routing creates a signaling architecture that reduces the cost and complexity of the core network and enables core networks to grow incrementally to support increasing service and traffic demands. It also facilitates network monitoring by providing a centralized vantage point in the signaling network. A centralized Diameter router is also the ideal place to add other advanced network functionalities like address resolution, Diameter interworking and traffic (roaming) steering.