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Subsections

LEAP: The Lightweight and Efficient Application Protocol

The Lightweight and Efficient Application Protocol, or LEAP, is the general framework for a set of high-performance, efficient protocols which are ideal for mobile and wireless applications. LEAP is designed to address all the technical requirements of the wireless data communications industry, and is oriented towards providing the greatest benefit to the industry and the consumer.

The LEAP protocols are patent-free, and open-source implementations of the protocols are available for a variety of devices and message-center platforms. The protocols are thus ready and available, and can be quickly distributed and implemented as a viable alternative to WAP.

A Brief History of LEAP

LEAP originated in 1994 as part of the research and development initiatives of McCaw Cellular's wireless data group (now AT&T Wireless). At that time McCaw Cellular was fully committed to paging, had recently purchased two nationwide narrowband wireless PCS licenses, and wished to develop an efficient wireless message transport and delivery system. Neda Communications, Inc., an independent consulting company working under contract to McCaw Cellular, played a significant role in the development of the required system. Neda Communications had also been involved from the outset in the development of the CDPD specification.

In 1997 however, soon after the purchase of McCaw Cellular by AT&T, the company abandoned narrowband PCS paging altogether. Prior to this event, Neda Communications had secured from AT&T the necessary rights to continue independent development of the protocols. Therefore, recognizing the eventual future need for these protocols, Neda then undertook to continue development of the protocols independently of AT&T. They were eventually completed by Neda, published as RFCs, and now form the cornerstone of the LEAP protocols.

Technical Overview of LEAP

In this section we will provide a brief technical overview of the LEAP protocols. For a detailed description of LEAP, refer to The LEAP Manifesto at http://www.freeProtocols.org/eaps.

LEAP is a set of wireless application protocols that are optimized for delivering small messages over wireless networks. Wireless networks are constrained by bandwidth limitations, and the hand-held devices they serve are constrained by limitations such as display size, battery capacity, and memory capacity. These constraints place a high premium on the efficiency of data transfer.

The LEAP protocols are up to five time more efficient than the ubiquitous SMTP e-mail messaging protocols. This increased efficiency translates into longer battery life for mobile phones, PDAs and other wireless Internet devices.

Layering of LEAP

The LEAP protocols are layered. The lower layer, called Efficient Short Remote Operation (ESRO), provides reliable connectionless transport services which can be used for a variety of applications. For example, in addition to mobile messaging services, ESRO can be used as a transport service for credit card verification applications and efficient micro browsers. On top of ESRO is the layer called EMSD. EMSD is a messaging protocol that is highly optimized for the submission and delivery of short internet mail messages.

ESRO, Efficient Short Remote Operation

All efficient applications have the requirement for an efficient transport mechanism. For this reason, the initial focus of the protocol development effort has been on creating a general efficient transport mechanism. The resulting protocol is referred to as Efficient Short Remote Operations, or ESRO. ESRO is a reliable connectionless transport mechanism, forming the foundation for the development of efficient protocols when TCP is too much and UDP is too little.

EMSD, Efficient Mail Submission and Delivery

The Efficient Mail Submission and Delivery (EMSD) protocol is built on top of ESRO, and is designed to address the Mobile Messaging application.

Initial Focus: Mobile Messaging

The need for efficient protocols extends across all aspects of wireless data communications, including e-mail, web browsing, and other applications. The LEAP architecture accommodates all of these applications. The initial LEAP protocols, however, are designed to support the mobile messaging application, since this is the dominant application for wide-area wireless networks.

Processes and Procedures

RFC Publication

Both protocols have been published as Internet RFCs; ESRO in September 1997 as RFC-2188 [2], and EMSD in March 1999 as RFC-2524 [1]. RFC publication is the mainstream Internet publishing procedure, ensuring that the protocols are freely, easily and permanently accessible to anyone who wishes to use them.

Freedom from Patents

As discussed in The WAP Trap, a highly desirable attribute of an industry standard protocol is that it be free from patents. The presence of patented components within a protocol undermines the ultimate purpose of the protocol: its unrestricted adoption and usage.

Neda has declared to the Free Protocols Foundation that the LEAP protocols are patent-free to the best of its knowledge, and that it intends to keep them patent-free permanently.

Open Maintenance Organizations

To provide an open forum for the continued development and maintenance of the LEAP protocols, Neda has established a public organization for each protocol.

The ESRO and EMSD protocols are maintained, respectively, by ESRO.org at http://www.esro.org/, and by EMSD.org at http://www.emsd.org/.

Each of these organizations allows public review of the respective protocol, and provides mechanisms for the correction and enhancement of the protocol as a result of collective experience.

Any interested person may become a member of these organizations and participate in the further development of the protocols. Participation in the development process is entirely open and non-exclusive; there are no membership fees. The only requirement for membership is that participants must adhere to the principles and procedures of the Free Protocols Foundation, thus ensuring that the protocols remain permanently patent-free.


next up previous contents
Next: Comparison of LEAP to Up: LEAP: One Alternative to Previous: Introduction   Contents