Brains & Brawn

SS7 networks provide a way to arm the wireless industry intelligently.

SS7 networks have given wireless-service providers the muscles to compete by creating enhanced services. However, an increased number of subscribers and services can hinder network operations and result in poor service. By harnessing the intelligence in SS7 data, providers can add the necessary balance of power between wireless growth and network efficiency to be victorious.

Over the past decade, most providers have converted to SS7-network trunking. By replacing initial signaling schemes such as multifrequency trunking, providers have realized benefits such as reduced call-setup times and improved seamless roaming capabilities. Providers also have reduced fraud through pre-call validation and the use of real-time intelligent analysis capabilities.

Most importantly, SS7 is enabling the development of enhanced services such as calling-number delivery (CND), single-number service, SMS and prepaid cellular. These types of enhanced services have led to tremendous growth in subscribers and revenues. Figure 1 on page 28 illustrates a typical set of network elements that communicate with one another via an SS7 wireless network.

The Arena Subscriber growth in the wireless industry is continuing at a phenomenal pace. The Yankee Group predicts there will be 1.26 billion wireless subscribers by 2005. This growth is leading to increased network usage and the introduction of more complex intelligent, enhanced services.

In addition to subscriber growth, the competitive nature of the industry is forcing higher network usage. Competition among wireless operators to obtain subscribers is creating new standards such as national and international footprints with seamless roaming and flat-rate calling plans with free nationwide roaming and long distance. These plans are driving subscribers to use wireless phones more often and, in some cases, as the primary phone.

Customer acquisition also is becoming increasingly difficult. To attract new customers, wireless providers are developing and offering many new enhanced services such as over-the-air provisioning, CND, enhanced location-based 911, calling-party pays (CPP), circuit-switched data and Internet browsing. As these new services become more complex, they place greater strain on SS7 networks. The demands placed on the wireless intelligent network also will increase significantly in November 2002 with the FCC-mandated introduction of wireless number portability (WNP).

These network strains are presenting three key challenges for providers including the ability to handle customer inquiries, cost-effectively manage interconnection agreements with wireline providers and effectively optimize wireless networks.

There is an imminent need for wireless-service providers to combat the rising costs of providing service. This power resides in the data carried and stored by the SS7 network. For any wireless signaling such as IS-41 for CDMA, TDMA, AMPS and GSM, the SS7 network transports and holds a vast source of information.

By using this information, business intelligence systems can collect SS7 data and make it available and accessible to various key stakeholders for specific data analysis.

Customer Service Customer-service costs continue to rise. With more subscribers and services to support, wireless providers are facing increased customer-service calls to report difficulties accessing the network, dropped calls or the malfunction of enhanced services such as SMS and call forwarding. In most cases, an inquiry cannot be adequately answered or the problem is referred to a technical group with access to switch call records. The latter solution takes even longer and still can be inconclusive. In either case, the provider is left with a dissatisfied customer.

Customer inquiries can be handled more efficiently by providing CSRs with access to SS7-network information in real-time. Some simple scenarios demonstrate the applications of SS7 in customer service:

- A customer reports that call forwarding did not work at approximately 5 p.m. The CSR queries the SS7 transaction information around that time and notes a 5:01 p.m. call that was sent directly to the wireless phone instead of the forwarding number. The CSR also discovers the cause code given for not invoking call forwarding: "authorized but deactivated." The CSR then instructs the customer on the procedures to activate call forwarding.

- A customer reports a dropped call. The CSR queries the network and finds a handoff message with a cause code of "weak signal." The CSR informs the customer that the call dropped during a handoff with a weak signal and also tells him that the provider is checking the location of the dropped call for a possible "dead spot" that would require improved coverage.

- A customer reports a missing SMS message. The CSR queries the network and finds a SMS failure message with a cause code of "network resource shortage." The CSR informs the customer of a network-capacity problem that is being resolved. If the cause code was "address-translation failure," the CSR informs the customer that the sender of the SMS message entered an incorrect destination number.

With access to SS7 transaction history, CSRs can handle customer inquiries with greater speed and efficiency. This enables providers to reduce direct customer-service costs. Figure 2 illustrates the type of SS7 messages that can be captured for near real-time analysis. In this example, the information explains to a CSR why the call was not delivered.

Interconnection Agreements In the past, wireless providers typically had a few interconnection agreements with wireline providers. Costs were based on the exchange of local traffic and charged at reciprocal rates ranging from 0.005› to 0.015› per minute. Exchange of local traffic was complex to monitor and sometimes resulted in litigious disputes. Today, the situation is becoming even more complex.

First, there is a higher amount of traffic exchanged between wireless and wireline providers that relates directly to the increase in network usage. As a result, interconnection agreements are becoming more costly for wireless businesses. It is important to find a method to monitor the actual traffic occurring under an agreement to avoid costly billing errors and potential litigation.

The interconnection agreements also are more complex with the introduction of new services. Wireless providers need access to wireline calling-name databases, which is usually billed on a per-dip (access) basis. Services such as seamless wireless/wireline roaming (where the wireless phone acts as a portable phone in the home and/or the office) and CPP are requiring wireless and wireline providers to cooperate in the collection and distribution of revenues. Figure 3 illustrates the increasing complexity of interconnection billing with the example of the CPP service. In the future, services such as WNP may require wireless providers to pay wireline providers for access to LNP databases.

In dealing with interconnection agreements, SS7 business-intelligence systems can track every transaction exchanged between wireless and wireline providers. For example:

- Through ISUP messaging, wireless providers can track every phone call between the two types of networks. In addition, providers also can track whether each call was completed successfully, if it is applicable to their interconnection agreements.

- Through TCAP messages, providers can track every database dip sent to a wireline provider and whether it was successful.

The ability to track every single transaction associated with an interconnection agreement ensures the accuracy of interconnection invoices, which helps avoid expensive billing errors and litigation.

Network Optimization Optimizing a wireless network is time- and cost-intensive. With more traffic on wireless networks, inter-MSC trunks and wireless-wireline interconnection trunks are facing congestion problems. Network problems such as equipment failure and poor signal quality are becoming difficult to identify and track. This is leading to higher capital outlay and traffic-analysis costs. SS7 business intelligence can provide relief.

Traffic engineering for inter-MSC trunks and wireless-wireline interconnection trunks has been a tedious exercise based on predictive modeling. In many cases, the models are not good enough and network-congestion still occurs.

With SS7 information available, providers can identify available capacity and peak usage on a trunk-by-trunk basis. This eliminates the need for predictive modeling and enables network augmentation based on real measurements. Over-provisioned routes can be identified, and facilities can be redeployed. By balancing the network, providers can create capital cost savings.

Other routes can be monitored and intelligently augmented when peak usage passes a threshold. Congestion problems also can be identified and resolved before affecting customers.

SS7 information also can help network and engineering operations to track handoff reasons, facility release reasons and enhanced-service cause codes for services such as SMS, call forwarding, call waiting, CND and 3-way calling.

Network-equipment failures can be identified and addressed pro-actively. Engineers can identify trends such as frequent handoffs due to weak signals. By monitoring SS7 subscriber-location messages, such as the IS-41 MSLocation message, signal qualities can be tracked for specific areas and lead to the identification of dead spots.

SS7 has armed the wireless industry with tremendous growth in the past decade. By harnessing the power of SS7 business intelligence, providers will continue to overcome the challenges of creating enhanced services and acquiring wireless subscribers.