Recent months have seen an increasing number of wholesale telecoms operators and other companies enter the market with inter-carrier IP exchange (IPX) services. Several developments will drive the long-term demand for IPX services, including the launch of 4G networks based on LTE, the growing demand among VoIP service providers for high-quality transit and termination, and the ability of IPX to support new services, including videoconferencing and HD voice.
By providing hub-based interconnection to telecoms operators, content providers and other companies, IPX service providers aim to offer a private international network for exchanging both IP and legacy traffic that is separate from the public Internet. As much as 25% of the wholesale value of traffic flowing over IPX networks is expected to be generated by new and value added services, with LTE interoperability, roaming and voice services set to be strong drivers for growth, according to telecoms analyst house, Innovation Observatory.
IP exchange (IPX) is a telecommunications interconnection model for the exchange of IP based traffic between customers of separate mobile and fixed operators as well as other types of service provider (such as ISP), via IP based Network-to-Network Interface.The intent of IPX is to provide interoperability of IP-based services between all service provider types within a commercial framework that enables all parties in the value chain to receive a commercial return. The commercial relationships are underpinned with service level agreements which guarantee performance, quality and security.
French operator group Orange’s wholesale division has expanded its IPX (IP exchange) with a Diameter signalling offering allowing customers to introduce LTE roaming across Europe, the Americas and Asia.The operator said that it has an ambitious program in place to extend it’s LTE Signalling capability through direct connectivity and peering agreements. According to the operator the Diameter-based LTE signalling service enables operators to provide end users with improved QoE on 4G networks while roaming outside their home country.
The Telenor Global IPX enables operators and partners to be connected through one IP connection. The IPX interconnect solution allows for an optimized, flexible, secure connection and guaranteed Quality of Service (QoS) for voice and mobile services. This is an important shift to improving Global Roaming Quality for the end customer. The Telenor Global IPX Service is provided over the IPX Compliant MPLS/IP Network and includes the basic framework designed by the GSMA which incorporates four main principles:
• Premium quality
• Secure environment
• Flexible for all services
• Cascading payments
To establish LTE data roaming worldwide, two architectural issues need to be addressed. First, it’s not that easy for an LTE operator by itself to complete interconnectivity with its global roaming destinations. Instead of current GRX and bilateral TDM links, roaming between LTE/EPC networks requires an efficient international exchange mechanism to integrate all the IP-based services originated in EPC/IMS and to interconnect them among numerous LTE operators worldwide. Besides, the existing GRX defines only best-effort IP transport, a QoS guarantee scheme between visited and home networks is required to let LTE subscribers enjoy international services with the same quality as domestic services.
Telstra Global is developing its capability to become a leading IPX provider in Asia-Pacific on a base of service flexibility for LTE roaming and service-aware traffic management. Telstra Global’s IPX strategy for LTE roaming borrows lessons from the cloud by offering its customers the ability to burst traffic in peak times. Telstra Global is also supporting the dynamic allocation of classes of service (CoS) to address the increased requirements of the content- and applications-based traffic expected to flow over next-generation networks. Telstra Global sees basic LTE data roaming as just the beginning of its IPX ambitions
Bear in mind , that instead of the legacy SS7 MAP in GPRS roaming, roaming signaling in LTE/EPC uses Diameter on IP to exchange subscribers’ authentication and location update between visited and home networks. Diameter is the Authentication, Authorization and Accounting (AAA) protocol succeeding to RADIUS. Unfortunately, interoperability of Diameter technology hasn’t yet reached full maturity. Actually, different vendors’ EPC nodes sometimes can’t successfully communicate to each other due to different implementations of Diameter signaling despite 3GPP standards.
Spectrum fragmentation is the big elephant in LTE roaming room .3GPP identifies more than 20 LTE Frequency Division Duplex (FDD) frequency bands and more than 10 LTE Time Division Duplex (TDD) frequency bands. According to Analysts, LTE operators have committed to launch in at least 13 bands, and with as many as 10 bands being proposed in a single region. It increases the cost for LTE operators to provide global roaming coverage with multiple bands, as well as for manufacturers to develop roaming-compatible handsets.
To solve this problem, the industry has to seek a set of common bands for international roaming or has to wait for a handset that supports a sufficient amount of frequency bands. Whereas the currently popular bands (800MHz, 1.8GHz and 2.6GHz) are likely to be applied for international LTE roaming for the time being, a global consensus on common bands for international roaming is necessary for sustainable growth of LTE and its roaming.
Despite the spectrum problem, a lot of MNOs, IPX providers, and vendors are preparing and testing LTE roaming now. Therefore, international LTE roaming will certainly expand particularly in the popular frequency bands. Thus, international LTE roaming on IPX embodies interconnectivity of IP-based telecommunication services among LTE/EPC ecosystems and reflects the beginning of new experience on global coverage of high speed mobile computing.
Recently SAP AG announced an IPX peering agreement with Etisalat UAE, the largest telecom operator in the Middle East and Africa, to deliver LTE roaming traffic to all mobile operators. This strategic LTE roaming and diameter peering agreement will help Etisalat operator companies to interconnect with SAP Mobile Services’ strong IPX customer community and launch LTE roaming quickly.
The Internet of Things is driving a lot of IPX conversations at the moment. Ericsson may have downgraded their forecast from 50 billion to 26 billion connected devices by 2020 – but that’s still a lot of billions – and it’s already 2016.For mobile operators, the opportunity is huge. But it comes with some pretty big challenges. For starters, it will mean a shift from ARPU to subscription-based billing models.
Moving from high-revenue, low-volume to low-revenue, high-volume is going to take serious economy of scale. That’s where IPX comes in. There are some operators and integrators who think existing network technologies such as GRX or IP are enough – but they’re missing something. Sure it might work on a small scale, but not at the scale or complexity (for example application tolerances) that IoT promises. IPX offers not just the scalability, but also the signaling functionality to make cross-border IoT traffic manageable.
Sadiq Malik ( Telco Strategist )