The network of your dreams: Picking the ideal intelligent network infrastructure involves a comprehensive checklist of vendor criteria, including network applications, scalability and reliability

Envision a network environment where a wireless carrier conceives of a new subscriber feature for roaming, billing or fraud prevention and deploys it networkwide in the same month, the same week or even the same day.

This is the intelligent network architecture's primary capability and the foremost reason for the current thrust toward intelligent network deployment in cellular and PCS carrier networks.

Wireless intelligent networking will evolve in phases, the first of which has already arrived in the form of off-switch mobility management systems. Although PCS carriers have the advantage of designing and building their initial mobility management networks off-switch, incumbent cellular carriers are not sitting on the sidelines with antiquated, switch-based network solutions. Progressive service providers, be they PCS or incumbent analog and digital cellular carriers, are migrating their networks to the intelligent networks of the future.

Wireless evolution The cellular networks of the 1980s were built with limited if any roaming capabilities. A carrier could handle switching requirements for an entire metropolitan statistical area with a single switch, or a mobile switching center (MSC). Subscriber profiles and mobility management capabilities were provisioned and managed on the same MSC. Traveling outside a service area meant no more subscriber service.

But as wireless carriers started making cross-system roaming agreements, the complexity of managing customer profiles and billing for roaming customers increased exponentially.

Within a few years, wireless subscribers have come to expect seamless roaming wherever they travel in North America, and they expect to receive the same service attributes wherever they roam.

At the same time, the explosive growth in wireless subscribers requires that multiple MSCs be deployed to support a single service area. This, in turn, has led to an increased processing burden and the need to duplicate services in each MSC (Figure 1).

Loading each MSC with subscriber information and complex mobility management service logic introduces not only a provisioning, maintenance and testing nightmare, but it also burdens the MSC with far more processing requirements than it was designed to manage. Add to that the increased demand for more wireless voice and data services, and the MSC's capacity and processing capability are quickly depleted by subscriber profiles and service processing instead of switching and call completion.

The prospect of investing in even more MSCs has given rise to an urgent need for alternative network solutions.

The problem is compounded for wireless operators with multiple and disparate switch types deployed in their networks. The need for transparent subscriber services in a multivendor MSC invoked is a tricky proposition that requires competing MSC vendors to coordinate switching capabilities to support the required services.

Achieving a uniform development timetable between competing MSC vendors rarely happens, so a wireless operator is restricted to a limited service rollout that depends on each MSC's capabilities.

Depending on MSC vendors for rapid software development cycles to deploy complex call processing services has frustrated wireline and wireless service providers for years. Dealing with two or more MSC vendors only exacerbates the problem.

Management on the go The concept of intelligent networking is simple. The originating MSC suspends calls and passes the calling information to an off-switch network-grade computer, referred to as a service control point (SCP). The SCP dispatches the information to the appropriate centralized software applications and databases to obtain information needed to proceed with call treatment. The SCP redirects the information back to the MSC, regardless of the switch type, enabling the call to be switched and completed as the centralized application designates (Figure 2).

It didn't take long to discover that centralizing services on an off-switch network-grade computer would relieve the MSC of many onerous processing and capacity requirements. The intelligent network has had a painfully long transition from a network concept to a critical component of wireline and wireless networks.

Until recently, skepticism continued about the justification of financing an intelligent network infrastructure and identifying the applications beyond line information databases and 800 service portability that would drive intelligent networking's success.

But the demand for processing and capacity relief in wireless networks has catapulted the wireless industry to the forefront of intelligent networking deployment. This trend has been driven by the differentiation and rapid service deployment required to be competitive, as well as the network management need to relieve the strain imposed on MSCs from the unprecedented growth of wireless subscribers and services.

The most logical intelligent networking application to be centralized in a wireless network is the home location register (HLR). The HLR profiles the subscriber, including location and service attributes.

Yet the HLR is more than a subscriber database-it is a mobility management application that analyzes a call's origin, destination, the subscriber's service attributes, and the proper routing and call treatment.

The HLR will profile the subscriber if the MSC launches a query. In many instances, the originating MSC can determine the call processing requirements and will not launch a query to the HLR application. However, as more complex services are deployed and an increasing number of subscribers rely on roaming capabilities, the HLR will be called upon more frequently.

To deter cloning fraud, it makes sense to centralize the authentication center on an SCP. The authentication center validates a subscriber's handset at the point of registration, call origination, or call termination. Wireless operators can virtually eliminate cloning fraud for networks and handsets that are authentication-capable.

How to select a vendor Major MSC vendors are developing off-switch intelligent network platforms or partnering with existing vendors for off-switch HLR, authentication center and enhanced services applications. A network planner should consider several attributes in evaluating the best vendor of SCP and intelligent network applications.

Interoperability is essential to off-switch network applications. The off-switch system must be able to provide seamless service to all the MSC types deployed or planned for the wireless network. Be sure that the intelligent network vendor has a significant track record or at least a concrete development plan of interoperability with the MSC types anticipated in your network. Investigate the vendor's relationship with MSC vendors to determine if cooperative planning is being done to develop network services. Does the vendor's relationship with MSC vendors go as far as lab testing to verify and certify software releases?

Quality. Does the vendor provide a reliable network-grade solution? Has the intelligent network vendor's infrastructure equipment been tested and certified to the minimum reliability level that the carrier is willing to deploy in its switching network? NEBS compliance is one such gauge of reliability.

Another gauge is the system's fault tolerance. A reliable intelligent networking solution provided across a mated pair configuration of SCPs should have a level of synchronization and load sharing that guarantees zero downtime for the network, even during system maintenance and software installation.

When applications or system upgrades are installed in a mobility management platform, the maintenance must go unnoticed by the subscriber base. An intelligent network vendor should be able to articulate and demonstrate how SCP middleware or applications can be added or upgraded with zero effect on the basic system functionality.

If this cannot be guaranteed, you must account for some level of service disruption to subscribers during scheduled maintenance. This level of exposure is intolerable to most network providers. A reputable vendor will provide such a guarantee, supported by financial penalties for network outages caused by maintenance or system failures.

Because most wireless carriers don't want to risk a single-node intelligent network system for mission-critical applications such as HLR, they require a mated SCP pair for redundancy. However, for a carrier that is willing to consider a simplex SCP solution, the carrier should still expect the vendor to engineer a system that optimizes data integrity and CPU efficiency, and provide a minimal level of parallelism. Parallelism allows for distribution of databases, applications and processing activity over multiple processors in a single system. Even a simplex system can be configured for a significant degree of fault tolerance and efficiency.

Other economical yet redundant system configurations besides a two-way mated are available. For example, a system may be configured in a three-way, four-way or higher configuration with full synchronization and redundancy between the SCPs. Wireless carriers should inquire about an intelligent network vendor's ability to provide systems solutions in a variety of configurations to provide redundancy and economy.

Scalability is another important factor. A system that has a linear increase in performance as processing power is added for more transactions or applications is a reasonable benchmark of efficient scalability. This would be a less important consideration if subscriber growth was not anticipated or if the intelligent network system being purchased would accommodate the projected subscriber and transaction growth for many years.

But the more likely and efficient scenario for most wireless carriers is to purchase an economical system large enough to meet the short-term network and subscriber demands, yet easily and economically expandable to meet any level of subscriber growth or applications complexity. That means a system's expandability becomes a major economic consideration.

A vendor may provide what appears to be a high-performance and cost-effective system solution for a specific number of subscribers in a network. However, unless the wireless operator properly accounts for growth, it could easily find itself in an inefficient and expensive dilemma of stringing together multiple systems to accommodate the necessary expansion. Such an unwieldy configuration could also lead to excessive thrashing of information between the network systems.

Service Development Agility. Development agility comes in two flavors: the service creation environment provided by the vendor, and the software development cycles and support of the software vendor.

Some intelligent network vendors tout the service creation environment that comes with their system solutions. The service creation environment provides easy-to-use software development tools that let a carrier design, build, test and execute its own call processing logic and subscriber services.

A wireless operator willing to devote systems engineering and development staff to creating intelligent network services should consider an intelligent network vendor's service creation environment capabilities. In today's environment, however, many wireless carriers do not have the engineering, programming or testing resources to create intelligent network software solutions that can be developed rapidly and more efficiently by a third-party software provider.

Most carriers prefer to concentrate their engineering efforts on network design, operations and network integrity issues rather than intelligent network service creation.

Although in-house service creation capabilities may seem more desirable, the ongoing software planning, development, testing, provisioning and support provided by the intelligent network vendor is more important in today's fast-paced software development environment. The vendor should be able to outline its system development cycles, feature development and system architecture plans, quality assurance, software migration policies and ongoing support levels. These attributes are a reliable gauge of a vendor's development capability and agility.

Cost. The most common gauge used to compare the cost of intelligent network systems is cost per subscriber. Carriers must pay close attention to the underlying assumptions when comparingthe prices of competitive vendors. They should be certain that all vendors are basing their pricing levels on an equivalent number of subscribers and that the cost per subscriber does not vary wildly at different subscriber levels.

For example, a vendor may provide a low-end system solution for 100,000 subscribers at $2 per subscriber. However, caution must be taken to ensure that expandability to 1 or 2 million subscribers does not lead to a major degradation in performance and a price tag of $8 per subscriber. Be certain that the gauges show the transaction rates, system requirements and total cost per subscriber at multiple subscriber volumes.

The same precaution holds true for performance statistics. In fact, price per subscriber depends to a large extent on the performance statistics.

Therefore, the definition of transactions per second-and the levels of system load at which transactions per second are measured-must be clearly and consistently compared between vendors. Intelligent network vendors should also be able to provide guarantees for consistent performance improvements over several years. This is especially important because the complexity of features and capabilities anticipated in the next five years will probably increase the number of call processing transactions per subscriber by a factor of four.

Open Development Platform. Carriers should ask several questions when choosing an open development platform. Does the hardware and middleware lend itself to compatibility with multiple applications? If so, then independent software developers likely will leap at the business opportunity to develop enhanced services that complement the anchor applications provided by the vendor. For example, if the intelligent networking platform is purchased for the HLR application, can the same platform be expanded to include authentication center, enhanced 911, location services, local number portability, prepaid services, wireless/wireline integration and efficient routing? Can the platform accommodate these applications without performance degradation?

Perhaps the vendor already has alliances with independent software developers and cooperatively plans to develop enhanced services applications. Carriers should investigate the level of engagement that the intelligent network has with independent software companies. This consideration could be tremendously valuable to a wireless operator's evaluation of future applications development.

Standards are another important development factor. What is the level of compliance to industry standards? Proprietary implementations may lock the carrier into a single vendor for switches and intelligent network applications.

For example, the IS-41 standard adopted by the Telecommunications Industry Association for mobility management network messaging is IS-41-C. If an intelligent network vendor of IS-41 applications fails or partially complies with Revision C, an inquiry should be made into the vendor's plans.

Bear in mind that non-compliance with the current standard is often necessary to provide a capability to the marketplace before a standards body fully defines and approves it.

A non-compliant feature may be an indication of a progressive vendor that is providing capabilities to carriers that are not willing to wait for standards to catch up with market demands.

No progressive intelligent network vendor with an established track record should be expected to provide a product line of applications that are fully standards-compliant. In fact, a vendor that touts a fully standards-compliant product line is likely a newcomer to the intelligent network and may not have a robust product suite in production.

WIN strategy. The wireless intelligent network (WIN) is the next generation architecture for wireless services. WIN is still being defined by the TIA TR45.2.2.4 WIN Task Group. In the meantime, vendors are planning their intelligent network solutions, and wireless operators are planning their network infrastructure around an eventual WIN architecture.

The emergence of WIN will promote a distributed wireless network infrastructure of service nodes. This concept will allow for greater interoperability of multivendor applications and network nodes. Some intelligent network applications may provide only an enabling function or contribute a small component of information to activate a subscriber feature.

The wireless operator will be able to define and easily create its own, unique subscriber services by piecing together the enabling functions provided by intelligent network vendors. Consequently, vendors may provide only the service components, instead of the complete features or services.

Any credible intelligent network vendor should be prepared to explain a minimal framework of its WIN development plans. A more progressive vendor may even have a prototype WIN architecture with WIN messages and service capabilities in the works.

As an increasing number of computer companies, MSC vendors and software services enter the intelligent networking market, wireless carriers are gaining a wider array of choices for intelligent network solutions. Such an environment is generally healthy for service recipients, but carriers should take precautions in screening and testing vendors' credibility.

Carriers should test a vendor's ability to respond to any of the aforementioned issues before going with an unknown. Be careful about distinguishing between system capabilities that the vendor describes as "feasible" or "under consideration" vs. system capabilities that are available, deployed and in production. Signing a contract for basic services that are still on the drawing board places a wireless operator at a major risk of not receiving the services on schedule, if at all.