Push and notification services

Our group's prototypical implementation of a Global System for Mobile Communications (GSM) Short Messaging Service (SMS) interface as well as our expertise with the Wireless Application Protocol (WAP) in general have been the catalysts in creating a relationship with IBM's Software Group Pervasive Computing (PvC) division to incorporate WAP push technology as well as short messaging services into IBM's Websphere Everyplace Suite (WES) Wireless Gateway (WG) product.

We have been responsible for designing and implementing the client application interfaces for both the Java and C programming languages. These APIs support message composition for short message services, for WAP push, as well as for e-mail through a common programming framework. Further features of the APIs allow to control the message delivery's quality-of-service, to query the status of the delivery, and to register notification handlers informing the client of the ultimate delivery status of a push request.

Clients interact with the Push Proxy Gateway (PPG) server using the Push Access Protocol (PAP) over an HTTP communication channel. PPG acts as the intermediary between the client and various wireless bearers such as GSM Circuit-Switched-Data (CSD), Mobitex MAN, or other WAP Wireless Data Protocol (WDP) bearers. Short message services are accessed through UCP and SMPP access protocols to the Short Messaging Service Center (SMSC). E-mail notifications are forwarded using the Simple Mail Transfer Protocol (SMTP). The architecture is illustrated by the picture below.

Services provided by PPG include message validation, message persistency, message enqueuing if delayed delivery has been specified by the client, the optional selection of particular wireless bearers, the notification of final delivery if requested by the client, and shielding the clients of lower layer bearer idiosyncracies. For WAP content, PPG also provides services to tokenize mark-up content respectively to compile script content. For GSM SMS, PPG includes support for non-Latin alphabets such as Chinese, Japanese, or Cyrillic.

While development efforts continue to strengthen and widen our offering for an enterprise grade notification infrastructure product, we are also investigating novel uses of this technology. In a joint project with Cahoot, a UK-based Internet bank, we have explored a combination of our SMS notification technology with dynamic content adaptation of WAP pull content. We are also experimenting with intelligent messaging services based on active database technology available for relational database systems and our push technology thereby enabling semantically powerful yet cost-effective solutions for customer relationship management (CRM) situations. A possible system architecture is indicated below.