White Paper - Diametriq's DRE Solution for Sustainable LTE Networks

As mobile traffic grows, so will diameter signalling. The exponential growth of mobile data in the coming years will mean that operators will grapple with massive signalling traffic. Unless optimally managed, this can congest and even bring the network to its knees. To address this concern, the IETF and the 3GPP have defined the key functions of a new network element in LTE networks - often referred as the Diameter Signaling Controller (DSC). The DSC incorporates a number of functions including smart message routing, load balancing, interoperability and network edge capabilities. DiametriqTM, player in this segment brings to market its Diameter Routing EngineTM (DRE) in the quest to enable superior networks with enhanced stability and traffic management capabilities.

Market Push Factors

A few factors continue to play a prominent role in pushing the management of signalling traffic to the forefront of network design and implementation, making it one of the key elements in the overall network infrastructure. 

a) Firstly, the proliferation of 4G/LTE networks which means that there is going to be a larger amount of mobile traffic as more and more subscribers move to bigger data packages and subscribe to more data applications than ever before. This results in rapid increases in the volume of signaling traffic generated by continuous authentication, authorisation and management of mobility and charging functions in the core network;

b) Secondly, the tremendous growth in mobile devices as well as mobile applications resulting in users having multiple gadgets such as smartphones, tablets and laptops - all accessing data simultaneously (imagine receiving a Twitter notification on your phone while you are accessing your Skydrive on your WiFi-connected laptop and loading pictures from your tablet to your Facebook account). Everytime a user logs in/out, accesses an application, signs into accounts and switches profiles on any data enabled smart device, session and subcriber  information are logged into the system along with a host of other signalling information.

This multiplied by the number of applications and devices each user accesses in the course of the day, will create massive amounts of signalling traffic within the network;

c) Thirdly, service packages are becoming increasingly complex thanks to various enabling technologies. While this provides the much demanded flexibility and convenience to subscribers, it multiplies the amount of signalling data for each subscriber. For example, combining mobile data with WiFi off-loading where smart devices automatically detect and log in onto an available Hot Spot and bounce back when it goes out of range generates a lot of subscriber and session data into the network. Logging in and out of a network and between networks including between 3G and 4G and between PAYG and quota plans all create enormous amounts of signalling traffic, with roaming and tethering functionalities which are available on various smart mobile devices further exarcebating the situation; and

d) Finally, the expected growth of new technologies, for example mobile WiFi will just add more load. So will other inventions such as SIM enabled electronic devices that consistently produce huge volumes of signalling traffic into the network.  

IP Modernisation and Fixed Mobile Convergence

Creating the Edge

As a niche provider specializing in DSC solutions, Diametriq is focused on providing the exact solution that befits the different architectures and varying requirements in the market. Apart from its full-suite solutions, Diametriq is also packaging standalone products, such as the DEA and IWF for specific use cases. This enables Diametriq to fulfill specific solution needs for some operators while being able to address the needs of more evolved architectures and respond to the kind of signalling traffic that is expected in the future, especially on LTE networks. Ongoing interoperability trials, including the recently concluded trial with TNS and ClearSky and successful connection to Tekelec's DRA further demonstrate Diametriq's capability to integrate its solutions with pre-existing components and hence provide more implementation options to Operators.

Diametriq's DSC solutions are delivered on the following technical specifications: 

50,000 diameter messages per second per blade (based on recent lab tests) on Intel Xeon, 2.40 Ghz, running at 10 ~ 12 % load.

Current Standards Compliance –3GPP R8, 9, 10, 11; GSMA IR.88; IETF RFC 3588/6733

Reference Points Supported – S6a, S13, S6d, S13', Gx, Rx, Gxc, Ud, Cx, Dx, Sh, Dh, SWx, S9, Gxa, Gxb, Gy, Gz, Ro, Rf, Sy

With its ongoing research and development intiatives in the segment, Diametriq is also expected to provide more innovative solution offerings in the market. Their research teams are already developing specialized apps with partners, for example the Diameter Roaming Visibility^TM which provides detailed analytics, including graphical map-based display and data session information of their roaming subscribers. 

The Market for DSC

According to Infonetics, global revenue for DSC increased 900% in 2012 compared to 2011. This figure came after Exact Ventures revised its earlier prediction by a 25% increase. It also expects the DSC cumulative revenue between 2011 and 2016 to approach $1 billion. Most operators are incorporating the DSC into their networks in response to the exponential growth expected from the impact of LTE and the growth in the use of smart mobile devices. Exact Ventures also projects the number of TPS (Ticks Per Second) to touch 235,000 per one million subscribers by 2017, a stark contrast to a 3G network where the number of signalling TPS in a Policy and Charging Control domain is typically less than 10 TPS. Diametriq sees that the market requires not only solid solutions but also reliable support and service maintenance capabilities over the long term, which will be an important factor in ensuring the effectiveness of any DSC solution.

Use Cases: Highlights from Diametriq DSC Solutions

Diametriq's DRE is a multi-component solution which can be deployed in combinations that best fit the network requirements. The solutions include Diameter Routing Agent (DRA), Diameter Edge Agent (DEA) and Diameter Interworking Function (IWF).  Each of these is defined by the 3GPP or GSMA and each plays a unique role in the Evolved Packet Core (EPC). 

The DRA is used when an operator has multiple instances of network elements like PCRF, PCEF and HSS as well as a substantial volume of signaling traffic. The DRA serves as a gateway concentrating the multiple signaling paths and provides load balancing and session binding functions.  A smaller operator with only one instance of these network elements will most likely not need a DRA.

The DEA is needed for LTE roaming providing security and topology hiding as well as simplifying the multiple signaling connections when an operator connects to an IP Exchange (IPX) or direct to another operator.  The DEA can be positioned at the MNO, the IPX or a hosted core provider.

The IWF is needed to connect with legacy network elements and applications, translating between older SS7 signaling and Diameter signaling.  It also manages vendor signaling variants. The necessity for an IWF is dependent on each environment. The DRA, DEA and IWF can be housed in separate servers as standalone elements or can be combined into a single server and support the following use cases:

1. Core Diameter Signaling Routing

Diameter interfaces are peer-peer with no central management resulting in a mesh with no  scalability or reliability in the network. The Diameter Routing Agent (DRA) provides: a. Load balancing to enable maximum usage of servers with failover and failback; b. Routing to enable flexible configuration of the network and independent scalability of the clients/servers; and c. Session binding and congestion management with Diameter throttling

2. LTE and VoLTE Roaming for Security and Topology Hiding

Security and topology hiding requirement during inter MNO connection necessitates an interface that provides these functions. The Diameter Edge Agent (DEA) provides security at multiple levels including TLS, IPsec, firewall and access control lists. It acts as the entry point to the home LTE network and supports all Diameter interfaces from the visitor LTE network. Security is provided across non-trusted domains and the visitor network does not need to be aware of the topology of the home network. Home networks can scale and be re-configured without affecting the visitor network configuration.

 

3. Over The Top (OTT) and Cloud Federated Service Delivery

Diameter signaling controllers manage Diameter traffic between a broadband provider and a MVNO or over-the-top/cloud provider, enabling new revenue-sharing business models, while ensuring an optimal user experience. This addresses exchange of authentication, charging and QoS information across network borders. The DSC can be part of various virtualized networks, thus cater to multiple customers at the same time. Also, in a truly virtualized environment, multiple DSC instances can be brought up in different configurations, each configuration addressing a subset of the customer base. Such an environment would provide capacity/configuration on demand. Cloud services are becoming increasingly popular and the DSC is highly amenable to a DSC-as-a-Service (DaaS) model.

 

4. Core Diameter Signaling Routing

4G networks need to interoperate with 3G networks, but not all operators will migrate to 4G at  the same time resulting in a hybrid of 3G and 4G network elements. The Diameter Interworking Function (IWF) provides an interworking capability for Diameter and SS7 that may be dynamically customized using script or plug-ins. The IWF can support MAP to/from Diameter (e.g., S6a, S6d, S13, S13’ to GSM MAP and ANSI41 MAP) and CAP/WIN to/from Diameter (e.g., Gy, Ro to CAP and IS-826 WIN. The DRE maintains existing CAPEX in 2G/3G elements and utilizes them in the 4G network, while enabling roaming with operators that have not yet transitioned to 4G.

 

5. Service Migration (A Diametriq Feature)

2G/3G services  which are based on SS7 using GSM/ANSI41 MAP, CAP or  WIN, can be migrated to the 4G network using the DSC. The applications can be hosted on or external to the DSC and can be Diameter-based or SS7-based. The DSC supports different variants of Diameter/SS7.

 

With the GA status on its core products, Diametriq is set to expand into new markets, especially tier 2 operators, strategic partners as well as IP Exchanges (IPX) and operators moving to LTE roaming. Among its upcoming projects include the deployment of the Diameter Edge Appliance for a hosted LTE core network provider who will use it to provide LTE roaming to their subscribers. With solutions that are highly scalable, adaptive and responsive to the changes in the increasingly complex network architectures, Diametriq's solutions is well poised to lead the market and provide best signalling traffic management solutions for the fast evolving mobile networks worldwide.