Even as radio technologies evolve to offer ever increasing bandwidths to subscribers, operators find themselves in an unenviable situation. They end up investing more on spectrum and infrastructure, but their revenues fail keep pace. Further, higher subscriber bandwidth lead to congestion in the network, resulting in poor customer experience.

Policy control of the network offers a promising solution to these twin problems. By prioritizing the traffic based on a host of criteria, new revenue streams can be generated. By better admission control and bandwidth allocation, congestion in the network can be controlled.

LiteCore Networks offers pre-built standard components to help equipment vendors and OSS/BSS developers develop standards-compliant policy control products.

Available interfaces

• Rx – Between Application Function (AF) and Policy and Charging Rules Function (PCRF). It allows Application servers to participate in policy control and it is a key component of IP Multimedia Subsystem (IMS).
• Gx – Between Policy and Charging Enforcement Function (PCEF) and PCRF. Used by PCRF to have dynamic control over the 3GPP access network.
• Gxx – Between Bearer Binding and Event Reporting Function (BBERF) and PCRF. Used by PCRF to dynamically control QoS parameters for non-3GPP access.
• S9 – Between PCRFs in the home network and the visiting network. Allows H-PCRF exercise dynamic policy control in roaming scenario.
• Gy – Between PCEF and On-line Charging System (OCS), allowing Service Data Flow based credit control.
• Gz – Between PCEF and Off-line Charging System (OFCS), providing off-line billing support.

Billing is at the heart of the service provider’s business. New types of services such as OTT video -and new ways of service creation such as using IMS, place more demand on the billing mechanism. Policy control adds another dimension to the complexity by offering different billing rates and plans for different customers/time of the day/QoS. Network equipment have to do more work to collect sufficient information for billing, and this information has to be communicated in a timely fashion either for real-time credit control or for near-real-time updates to the database.

LiteCore Networks (LCN) offers a number of standard interfaces that simplify the development of required functionality on the devices as well as on the systems in the billing subsystem.

LiteCore Compass Rf and Ro Interfaces

LiteCore Compass Rf and Ro interfaces implement the Diameter based off-line and on-line billing interfaces specified by 3GPP 32.299. The interfaces are available as C-callable APIs in object file format. Application developers also get a set of call-backs in source code format. Application behaviour can be controlled by customizing these call-backs.

The interfaces in turn use LiteCore Compass Diameter base stack to communicate with the remote application. Alternatively, they can be integrated with other 3rd party Diameter stacks. These interfaces have been developed using Compass ABNF Parser and Code Generator. This allows LCN to quickly support new releases of standards.

Product Features

• Simplified APIs hiding protocol details and complexity
• Customizable call-back mechanism
• Server and client side implementation
• Thread safety for scalable application development
• Professional services for any customization of your special requirements

All-IP LTE networks depend on IP Multimedia Subsystem(IMS) to deliver key services like voice and multi-media streams.

LiteCore Networks offers Cx/Dx and Sh interfaces for building CSCF and HSS, apart from Rx interface for policy control of multi-media data streams.

LiteCore Compass Cx/Dx and Sh Interfaces

LiteCore Compass Cx/Dx and Sh interfaces implement the Diameter based communication protocols between IMS components and the HSS. Cx/Dx interface provides support for user location and profile management. Sh allows Application Server (AS) to query user data. The interfaces are available as C-callable APIs in object file format. Application developers also get a set of call-backs in source code format. Application behaviour can be controlled by customizing these call-backs.

The interfaces in turn use LiteCore Compass Diameter base stack to communicate with the remote application. These interfaces have been developed using Compass ABNF Parser and Code Generator. This allows LCN to quickly support new releases of standards.

Product Features

• Simplified APIs hiding protocol details and complexity
• Customizable call-back mechanism
• Server and client side implementation
• Thread safety for scalable application development
• Professional services for any customization of your special requirements

LiteCore Compass Diameter stack implements IETF RFC 3588. While it is an integral part of interface suites form LiteCore, the stack is available separately to equipment vendors who need a multi-threaded, high-performance implementation.

Product Features

• Full compliance with RFC 3588
• Load Balancing
• TCP and SCTP
• TLS and IPSec
• IPv4 and IPv6
• XML based configuration
• Syslog based detailed logging support
• Dynamic log control
• Available as library or as application(daemon)
• Support for sever, client and relay roles

LCN Diameter Signaling Controller is now available as a Virtual Network Function, ready to be deployed in OpenStack or other cloud infrastructure. The product is available as qcow2 VMs. Other formats will be supported on request.

Policy control, billing and IP Multimedia Subsystem (IMS) and other sub systems are generating an ever increasing amount of Diameter control messages. Diameter Signaling Controllers (DSC) sitting in the path of these messages and intelligently routing them, hold the key to build a scalable, reliable network.

LCN DSC provides the following key features:

• Diameter Relay/Proxy/Redirection (RFC 6733)
• Load balancing and high-availability support.
• Diameter Routing Agent (DRA) functionality (3GPP TS 29.213):
  • Ability to forward related sessions on different interfaces like Gx,Gxx and Rx to the same PCRF.
• Configurable server selection
  • Based on IP Address, identity or APN.
  • Rule-based routing on any AVP present in the request
• Dynamic peer and routing table changes
  • With the OpenStack monitoring agent, provides a cloud ready solution.
• Centralized monitoring and control of the singaling traffic
• Along with LCN Compass APIs for different 3GPP interfaces, provides a complete control protocol environment for billing, IMS and policy control.

Operator Advantages

• Scalable and reliable signaling network with central control
• Topology hiding
• Interoperability with a large number of leading vendor products
• Ability to move Diameter services to the cloud

IoT is poised to be the next disrupter of telecom networks and business models. 3GPP Rel 13 introduces key capabilities required to support large number of IoT devices on the mobile networks.

The following features have a major impact on the Evolved Packet Core (EPC):

• Service Capability Exposure Function allowing application servers to query the network, device and subscription information
• Monitoring Enhancements (MONTE) allowing an Application Server to monitor MTC device or subscription related events

LCN has developed a set of Diameter APIs implementing the key interfaces needed in the control plane. As of April 2016, some of these interfaces are still undergoing revisions in 3GPP, but they are stable enough for implementation. LCN's APIs enable early developers to prototype and implement IoT enabling application servers. Further as standards mature, the APIs will remain unchanged, allowing addition of new capabilities with minimal effort.

The interfaces available now are:

• Np - TS 29.217, between Radio Congestion Awareness Function (RCAF) and Policy and Charging Rule Function (PCRF)
• Ns - TS 29.153, between Service Capability Exposure Function (SCEF) and RCAF
• Nt - TS 29.154, between SCEF and PCRF
• S6mn - TS 29.336, between Home Subscriber Server (HSS) and MTC-Inter Working Function (MTC-IWF)/MTC-AAA
• S6t - TS 29.336 between HSS and SCEF
• T6 - TS.128, between MME/SGSN and SCEF/IWK-SCEF

These, with other already available interfaces like Tsp and Rx provide the complete control plane interfaces for IoT applications.

LCN BSF and AP together allow UICC based mutual authentication between a device and the network or application, and can help operators provide security to IoT and other applications, using already available infrastructure.

BSF implements 3GPP Generic Bootstrapping Architecture, authenticating the UICC/SIM based device - and letting the device authenticate the network. It uses Diameter Zh interface to interact with HSS for subscriber information. Standard AKA protocol is used for authentication. Standards conformance: 3GPP TS 33.220, TS 29.109, RFC 6733 and related standards.

Authentication Proxy offers a front-end to http based applications on the device, and interfaces with BSF to implement bootstrapping a secure connection to the Network Application Function. 3GPP Zn interface is used between AP and BSF. Standards conformance: 3GPP TS 33.222, TS 29.109, IETF RFC 6733 and related standards.

Optionally AP can be colocated with the NAF, allowing end-to-end encryption of application data.