Geographical routing – flexibility is essential
Location is often a key variable for the optimum delivery of a service. There are numerous methods for determining user location and each has evolved for different purposes and to suit different network environments. By combining these into a single location function, we’ve enabled more efficient service delivery as well as novel revenue opportunities for our operator customers.
Where should we route a call?
When taking a decision on where to route a call placed to a non-geographic number, such as a universal access service, emergency call handling, or a specialised closed user group, the location of the calling party is often an important factor. If the call is to a business freephone number, the organisation that owns this number may wish the call to be routed to the nearest branch office or location to the calling party, for example.
Similarly, if the call is to emergency services, it’s essential to be able to locate the calling party, so that the most appropriate response can be made. However, there are multiple ways in which location can be determined. The calling party used to be key, as numbers were related to fixed geographical domains. Mobile and number portability changed this as, in most countries, the location became decoupled from the number associated with a user.
Location granularity and resolution depend on network technology
To discover the location of a mobile subscriber, a simple request mechanism can be initiated to the mobile network, either directly to an HLR / HSS, or via a location server that is deployed for this purpose. Similarly, location information can also be provided in both the Initial DP message in a CAMEL flow, as well as to some extent using the P-Access Network-Info (P-ANI) in SIP-based IMS networks.
Other techniques include reference to a positioning server, GPS resolution, traditional geographic number resolution (for fixed numbers), or even postcode checks from a CRM.
Each method gives varying degrees of accuracy, allowing some resolution of location to be obtained so that the call can be processed.
We have handled this with a variety of mechanisms, selecting each according to the needs of the network and operator’s planned service. Through time, this has become increasingly complex. As a result, we updated our routing module to consolidate the options into a single decision path.
Efficient location discovery
GeoRouter is a key element in our service logic. It’s not exposed directly to users but it’s a key element for operators. It handles destination selection for calls to a specific service and includes all of the listed methods of resolving location for fixed and mobile subscribers as an integrated module. The routing is applied independently from the method location applied.
In any particular deployment, at least some of these will be available, depending on the integration that is required or that can be achieved.
As a result, our operator customers can choose the most appropriate options for their network and service portfolio and the capabilities available. Perhaps more importantly, they can use location resolution to introduce subsequent service extensions.
They may, for example, wish to deliver a service to fixed customers initially, and then extend to mobile customers, introducing new location resolution capabilities as they do so.. Or vice versa. This change makes such migrations much simpler, allowing them to be accomplished gracefully. By including all methods in a single module, operators can more easily evolve offers and avoid using additional systems, making the whole process more efficient for real-time session control.
And, it allows operators to add new features. For example, one of our customers allows its business customers to use location as a service. They can make location / positioning requests to the mobile network but are charged a flat fee for doing so. This provides revenue to the operator while enabling businesses to optimise their own service delivery. By consolidating all methods into a single logical feature, we’ve added greater flexibility and extended revenue opportunities for operators, increasing ROI.
Flexibility to enable specialised public safety applications
It also has a role in public safety. In another case, there is a specialised national short number for reaching cardiac specialists across the country-wide hospital network. There are many members of this group, but they are distributed. The GeoRouter function enables selection of the right member of this specialist team to be reached, based on the best available location resolution.
Once the nearest specialist is identified, additional logic is applied to ensure successful routing, in the event that the original choice is unavailable. GeoRouter can thus be combined with queueing and other behaviours to create a seamless service flow, with exceptions and fallback options.
Sometimes, when we talk about product evolution or development, we’re referring to a specific feature that’s visible to an end-user. However, just as much evolution takes place in the underlying service handling capabilities we deliver – features such as GeoRouter are invisible to end-users. But, they are key to customising and tailoring services to match network capabilities and the ways in which services are delivered.
We’re continually implementing such enhancements, not just because they give new capabilities and flexibility to our customers, but also because they allow true integration with the features inherent in each network. Complex integration is fundamental to what we do. It’s how we convert service delivery ideas into practical solutions – which can both meet public service requirements, as well as uncover new revenue streams.