Operators in developing countries face different challenges compared to Tier 1 operators when it comes to making the move from TDM digital switching to a Voice over IP (VoIP) paradigm. While the industry talks of the move to Next Generation Networks (NGN) and IP Multimedia Subsystems (IMS), the applications on the ground are still elusive for carriers in developing markets. Yossi Ben Harosh, President & CEO, Telrad Networks, analyses the situation.
Operators need to ask themselves two central questions. Firstly, what is the return on investment (ROI) and the actual cost-saving of moving to an IP core? Secondly, what are the technological risks associated with such a move?Every case is unique
Several of the world's leading carriers have already successfully implemented a softswitch-based IP transition in their core infrastructure and illustrated the many benefits of a successful deployment. Operators have found that softswitch-based architectures enable them to pursue the lucrative revenue opportunities presented by advanced services which only softswitches can support.
Once properly installed, this architecture has also been shown to widen the profit margin on commoditised services by transporting the traffic more efficiently. The benefits are in fact so pronounced that this is almost universally recognised as the inevitable standard for switching infrastructure for any future network.
That being said, an immediate softswitch implementation is not necessarily the wisest investment for every operator just yet. In some regions, demand for advanced services is already at levels which would justify a softswitch deployment. In many others, the implementation challenges dictate a more gradual transition. Even where demand is still lacking, some operators have tried to push ahead with softswitch implementations for the sake of making their network forward-compatible with future hardware investments. Particularly, given recent developments in TDM-IP interoperability technology, the cost-benefit balance for a gradual transition has become increasingly attractive for many operators around the world.
Many operators are now examining their options regarding their IP transition strategy and softswitch deployments, and there is no general rule to determine the decision in all cases. The local conditions in each market, and each operator's currently deployed network architecture, must be considered in designing the right IP transition strategy.Updates from the field
Experiences from the field are mixed. Following reports of the first profitable deployments, other operators have rushed to emulate these success stories and found that they may have underestimated the technical challenges involved. While a wide variety of operators have implemented policies of purchasing only IP-based switching systems, the truth is that implementing such solutions is far from straightforward. In implementation after implementation, operators have purchased softswitches only to find that the integration of the softswitch takes longer, costs more, and is more challenging than originally planned.
First of all, making the change to an IP backbone has its set of challenges, and operators want to make sure the transport system is working before going out to the edges with IP based telephony.
Secondly, making the technological transition without impact on the service to customers is a challenge. The system needs to work with existing peripherals or go through complex configuration to implement all of the features available with Class 5 switches. Add to that the complexity of provisioning subscribers in a new switching system.
Unfortunately, experience has shown that this transition is so complex that it almost never is completed within the scheduled time frame. Transition to softswitches is so time-consuming that numerous operators find that even after delivery and installation, it takes over a year to actually be ready to implement them in live deployments.
Finally, and most importantly, in many cases there is no justification for retiring the existing TDM Class 5 switches. For example, in India, a huge investment has been made in TDM switches, an investment that has not yet provided a full ROI to the operators. In cases like this, existing switches are not being phased out at all. While the operators may add softswitches for additional capacity, the existing digital switches are still fully functional and providing the lowest cost solution.Gradual transition
For operators in emerging markets, the risks of making the move to IP networks are quite intimidating. Although the prospect of improving the service offering is tempting, in much of the developing world, advanced services are still far from being mass-market demands. In these areas, the main issue is just providing low-cost access and being prepared for future transition to IP networks.
With these requirements in mind, it often makes sense to choose a softswitch that will provide the fewest other network changes. Vendors such as Nortel have taken an approach that allows gradual transition, preserving existing services and peripherals, while providing a future-proof platform for support of future IP and triple-play services. This kind of low-risk and low-cost approach can provide a high level of availability of existing services, while allowing a transition to take place over time.
Furthermore, existing operators who need to make the transition to IP networks to the edge are in need of gateway solutions to work with existing Class 5 switches. For example, where WiMAX is used for access, operators are finding the most effective solution is to use a SIP to V5.2 gateway to provide fully-featured voice services through existing TDM switches, without making further changes in the core network. The same kind of service can be provided in a wide range of other access technologies through similar gateways. The gateways provide almost no risk to the operator. Such a solution can be up and running within hours, with no changes to provisioning or networks.Conclusion
As triple-play and VoIP services become the norm for telco operators, it is important to understand the financial and operational risks involved in making the transition from Class 5 switches to softswitches. Today's technology allows gradual transition from TDM to IP networks, dramatically lowering the risk and allowing more conservative financial planning for operators in emerging markets.