The LEAP protocols are intended to be an enabling catalyst for the growth of the wireless-IP based Mobile Messaging industry, and have been designed with this goal in mind from the outset. They have been designed as a genuine enabling technology which will bring enormous benefits to the industry and the consumer. They are a sound engineering construction based on true openness and patent-freedom.
The LEAP protocols a general-purpose solution to the problem of efficient message transfer, and their use is not limited to any particular device type or network. In particular, LEAP is compatible with all wireless-IP networks. Examples of wireless networks which provide native support for LEAP are CDPD, GSM, packet CDMA, and PCS.
The basic organization of the LEAP protocols is shown in Figure 1.
As shown in Figure 1, the LEAP protocols are layered. The lower layer is called Efficient Short Remote Operations, or ESRO. The ESRO layer provides reliable connectionless transport services which can be used for a variety of applications. For example, in addition to mobile messaging services, ESRO can also be used as a transport service for credit card verification applications and efficient micro browsers.
For more information on ESRO see the article ESRO: A Foundation for the Development of Efficient Protocols within The LEAP Manifesto, or visit the ESRO website at http://www.esro.org/.
One of the efficient application layers built on top of ESRO is called Efficient Mail Submission & Delivery, or EMSD. EMSD is the component of LEAP that addresses the Mobile Messaging application.
EMSD is a specialized native Internet messaging protocol. It defines a similar set of services to the existing SMTP protocols. It defines a complete set of rules for message submission (end-user device to server) and message delivery (server to end-user device). EMSD meets or exceeds the level of functionality, reliability and security provided by the existing SMTP protocols.
Though its use is not limited to wireless networks, EMSD has been designed specifically to address the requirements of wireless networks, such as CDPD, Wireless-IP, Mobile-IP. In particular, EMSD has been designed with a very strong and clear emphasis on efficiency.
EMSD is highly optimized for the submission and delivery of short (typically 4 kilobytes or less) Internet e-mail messages, and is therefore extremely well suited to the wireless environment. EMSD improves on existing messaging protocols by optimizing the exchange between the server and the end-user device, both in terms of the number of bytes transferred and the number of transmissions. Because of the required timeliness of the messages, mailbox access protocols like POP and IMAP are not used. EMSD is the only truly open messaging protocol that is specifically designed for the wireless network environment.
EMSD is a natural extension of the existing Internet e-mail environment, and accommodates the two-way paging model of usage, in which time-critical messages are "pushed" to the recipient.
Any network or network operator which faces significant bandwidth and capacity limitations can benefit from the use of EMSD. Any user of a network who must bear high costs for measured network usage can benefit from the use of EMSD.
The initial use of EMSD is expected to be primarily to provide Mobile Messaging services over IP-based wireless networks. However, EMSD can also function as an adjunct to Mail Access Protocols for "Mail Notification Services."
For more information on EMSD see the article EMSD: The LEAP E-Mail Component within The LEAP Manifesto, or visit the EMSD website at http://www.emsd.org/.
The Efficient Hyper Text Delivery (EHTD) layer is a hypertext transfer protocol which is optimized for the efficient transfer of short markup pages. EHTD is the component of the LEAP protocols which facilitates web browsing. Along with EMSD, EHTD also benefits from the reliable efficient services of ESRO. A multiplicity of efficient markup languages can be used in conjunction with EHTD. Development of the EHTD protocol is currently in progress.
Various other efficient application protocols are either under development, or anticipated for future development. One of these is the Efficient Dictionary protocol, or E-DICT, which will enable efficient access to dictionaries and other look-up data structures. A starting point for the E-DICT protocol is currently being created. In developing E-DICT, we intend to build on the existing work already done in the context of the DICT protocol.
We anticipate that additional protocols will be needed for a variety of future applications, not all of which can be foreseen at this time. These applications will include such things as efficient implementations of ESRO-based instant messaging, chat, white pages, and others.
