It is now time for a new generation of protocols to be implemented, designed to address the need for performance, rather than simplicity.
The Lightweight & Efficient Application Protocols, or LEAP, are designed precisely to address this need. 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 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 being made 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.
LEAP originated in 1994 as part of the research and development initiatives of McCaw Cellular's wireless data group (now AT&T Wireless). The development work that would eventually lead to LEAP was initially undertaken in the context of the CDPD network; its scope was later expanded to include the Narrowband PCS network also.
By 1996 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.
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
[65], available at
http://www.LeapForum.org/LEAP/Manifesto/roadMap/index.
html.
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.
The LEAP protocols are layered. The lower layer, called Efficient Short Remote Operations (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 e-mail messages.
Various other LEAP protocol components are in the process of being designed and implemented. See The Future of LEAP article in The LEAP Manifesto for more details.
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.
ESRO was published in September 1997 as Internet RFC-2188 [91]. Additional information about ESRO is available at http://www.esro.org/
The Efficient Mail Submission and Delivery (EMSD) protocol is built on top of ESRO, and is designed to address the Mobile Messaging application. EMSD provides for the submission and delivery of short (4 kilobytes or less) Internet e-mail messages. EMSD meets or exceeds the level of functionality, reliability and security provided by the existing SMTP protocols. EMSD is a great deal more efficient than existing Internet e-mail protocols.
EMSD was published in March 1999 as Internet RFC-2524 [5]. Additional information about EMSD is available at http://www.emsd.org/
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. Subsequent LEAP protocols are expected to address other applications as necessary.
We believe that a public protocol must conform to each of the following basic, fundamental principles:
Each of these provides a vital assurance of protocol integrity. Patent-freedom ensures that a patent-holder cannot subvert free-market competition among products and services based on the protocol. RFC publication ensures that the protocol is freely available to anyone who wishes to use it. And maintenance by open Working Groups ensures that development of the protocol takes place by democratic, rather than oligarchic, processes.
This trilogy of principles represent the most basic guarantees of the integrity of a protocol.
The LEAP protocols are intended to be open in the fullest sense of the word; they are intended to be freely and permanently available, subject to public review and revision, and without usage restrictions of any kind. Therefore the processes and procedures used throughout the development and maintenance of the LEAP protocols have been such as to endow them with these characteristics, and to ensure their integrity as public protocols.
Complete details of the LEAP development process are provided in a separate article within The LEAP Manifesto entitled The LEAP Protocol Development Model. The major aspects of the development process are summarized in the following sections.
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.
The development and maintenance of the LEAP protocols conforms fully to the policies and procedures of the Free Protocols Foundation. In particular, 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. For more information see http://www.FreeProtocols.org.
Both protocols have been published as Internet RFCs; ESRO in September 1997 as RFC-2188 [91], and EMSD in March 1999 as RFC-2524 [5]. 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.
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 enhancement of the protocol as a result of collective experience.
Any interested person may 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 is that participants must adhere to the principles and procedures of the Free Protocols Foundation, thus ensuring that the protocols remain permanently patent-free.