Chapter 1. Introduction

intermittent bandwidth, and extremely awkward input mechanisms. Most existing HTML pages do not work on mobiles phones, and never will.

WAP defines a completely new markup language, the Wireless Markup Language (WML), which is simpler and much more strictly defined than HTML. It also defines a scripting language, WMLScript, which all browsers are required to support. To make things even simpler for the phones, it even defines its own bitmap format (Wireless Bitmap, or WBMP).

HTTP is also too inefficient for wireless use. However, by using a semantically similar binary and compressed format it is possible to reduce the protocol overhead to a few bytes per request, instead of the usual hundreds of bytes. Thus, WAP defines a new protocol stack to be used. However, to make things simpler also for the people actually implementing the services, WAP introduces a gateway between the phones and the servers providing content to the phones.

Figure 1-1. Logical position of WAP gateway (and PPG)between a phone and a content server.

The WAP gateway talks to the phone using the WAP protocol stack, and translates the requests it receives to normal HTTP. Thus content providers can use any HTTP servers and utilize existing know-how about HTTP service implementation and administration.

In addition to protocol translations, the gateway also compresses the WML pages into a more compact form, to save on-the-air bandwidth and to further reduce the phone’s processing requirements. It also compiles WMLScript programs into a bytecode format.

Kannel is not just a WAP gateway. It also works as an SMS gateway. Although WAP is the hot and technically superior technology, SMS phones exist in huge numbers and SMS services are thus quite useful. Therefore, Kannel functions simultaneously as both a WAP and an SMS gateway.

Overview of WAP Push

Previous chapter explained pull mode of operation: the phone iniatiates the transaction. There is, however, situations when the server (called in this context a push initiator) should be the initiator, for

2

Page 9
Image 9
Nokia WAP and SMS gateway manual Overview of WAP Push

WAP and SMS gateway specifications

Nokia has long been a pivotal player in the telecommunications industry, and its contributions to mobile communication technology are numerous. Among these contributions, the Nokia WAP and SMS Gateway stand out as essential elements in enabling mobile internet access and messaging services in the early days of wireless communication.

The Nokia WAP (Wireless Application Protocol) gateway was introduced to facilitate mobile access to the internet and to allow users to interact with web services through their mobile devices. Built on a client-server architecture, the WAP gateway acted as a bridge between the mobile network and the internet, translating traditional web content into a format that mobile devices could effectively render. This conversion was crucial, given the limitations of early mobile devices regarding screen size, processing power, and network bandwidth.

One of the main features of the Nokia WAP gateway was its ability to provide users with real-time access to information such as weather updates, news, and stock prices. By using a lightweight markup language called WML (Wireless Markup Language), the gateway allowed developers to create mobile-friendly websites that could be accessed via WAP-enabled devices. This marked a significant step toward the mobile internet we know today, creating a new realm of possibilities for developers and users alike.

Another critical aspect of Nokia's offering was the SMS (Short Message Service) gateway. The SMS gateway provided a robust platform for sending and receiving text messages across various mobile networks. It enabled seamless communication between devices, regardless of the underlying technology. This feature made SMS a popular choice for both personal communication and business applications, such as marketing campaigns and customer service notifications.

The Nokia SMS gateway utilized established protocols, such as SMPP (Short Message Peer-to-Peer), to ensure reliable message delivery and efficient interaction between SMS applications and mobile networks. Its characteristics included scalability, allowing service providers to handle large volumes of messages, and flexibility to integrate with existing applications and systems.

In summary, the Nokia WAP and SMS gateway played a vital role in the evolution of mobile communication. With features that enabled mobile internet access and streamlined messaging capabilities, these technologies laid the groundwork for the mobile-centric world we live in today. Their legacy continues to influence mobile application development and the broader telecommunications landscape. As the industry progresses, the innovations introduced by Nokia serve as a reminder of the foundational technologies that paved the way for modern mobile experiences.