Attached is a short description that introduces
LEAP: Lightweight & Efficient Application Protocols
as an alternative to WAP.
The full description is part of the LEAP Manifesto.
------
LEAP: One Alternative to WAP
Mohsen Banan
<public(_at_)mohsen(_dot_)banan(_dot_)1(_dot_)byname(_dot_)net>
Version 0.3
June 23, 2000
Copyright (C) 2000 Mohsen Banan
Permission is granted to make and distribute verbatim
copies of this manual provided the copyright notice and
this permission notice are preserved on all copies.
1 Introduction
================
Over the last few years, data communications has
expanded dramatically and forcefully into the
wireless environment. A major new Internet
reality is that of wireless networks, providing
service to legions of miniaturized, hand-held
mobile devices. This reality has placed an
entirely new set of requirements on the underlying
communications protocols: they must now provide
the power efficiency demanded by hand-held
wireless devices, together with the bandwidth
efficiency demanded by wide area wireless
networks.
Existing Internet protocols do not adequately meet
these requirements. Therefore a new generation of
efficient protocols is needed, to satisfy the
demands of wireless applications. At some point,
the wireless data communications industry must
agree on a single set of protocols that satisfies
its requirements.
1.1 The WAP Trap
------------------
In April 1998, a business association called the
WAP Forum published the Wireless Application
Protocol, or WAP. WAP is a set of specifications
for wireless data communications using hand-held
devices such as mobile phones and palmtop
computers. The WAP specification provides the
users of these devices with mobile data
communications capabilities such as web-browsing
and e-mail. In a previous article entitled The
WAP Trap [4], however, we have argued that WAP is
utterly unfit for its claimed purpose.
2 The Need for Efficiency
==========================
Engineering is the art of making intelligent
trade-offs between conflicting requirements. A
perennial engineering trade-off is that which must
be made between the need for simplicity, and the
need for performance. In the case of wireless
data communications, performance means such things
as data transfer speed, power efficiency, and
bandwidth efficiency.
The 1980s and 1990s were the decades of simple
protocols - protocols such as the very aptly named
Simple Mail Transfer Protocol (SMTP), and Simple
Network Management Protocol (SNMP). A great deal
of the success of these and other Internet
protocols can be attributed to their simplicity.
However, things have changed. Network
communications has now expanded into the wireless
and mobile data communications arena, and wireless
applications demand efficiency. The move to
wide-area wireless has significantly shifted the
location of the ideal engineering balance between
simplicity and performance - moving it away from
simplicity, and towards performance.
We therefore need a new generation of
high-performance, efficient protocols, to cater to
the demands of wireless applications. The point
is sometimes made that the need for efficiency in
the wireless arena is a temporary one -- that
advances in wireless engineering technology in the
form of third generation (3G) systems will
eliminate existing bandwidth limitations,
obviating the need for efficient protocols. As
long as the capacity of wireless networks remains
finite, however, the need for efficiency will
persist. Efficient usage is an inherent
requirement for any finite resource, therefore the
requirement for efficient bandwidth usage and
battery longevity will remain.
Thus far, professional protocol and standards
producing associations, most notably represented
by the IETF, have failed to produce an acceptable
specification. The IETF continues to represent
the tradition of simple protocols, a tradition
which wireless communications has now made
obsolete.
3 LEAP: The Lightweight & Efficient Application Protocols
==========================================================
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.
3.1 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
[3], 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.
3.1.1 Layering of LEAP
------------------------
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'' section of The LEAP
Manifesto for more details.
3.1.2 ESRO, Efficient Short Remote Operations
-----------------------------------------------
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 [2]. Additional information about ESRO
is available at http://www.esro.org/
3.1.3 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. 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 [1]. Additional information about EMSD
is available at http://www.emsd.org/
3.1.4 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. Subsequent LEAP protocols are expected
to address other applications as necessary.
3.2 Processes and Procedures
------------------------------
We believe that a public protocol must conform to
each of the following basic, fundamental principles:
o Patent-freedom
o RFC publication
o Maintenance by open Working Groups
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.
LEAP protocols have been declared to the Free
Protocols Foundation as patent-free. For more
information see http://www.FreeProtocols.org.
The ESRO and EMSD protocols have been published as
Internet RFCs and 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.
Complete details of the LEAP development process
are provided in a separate article within The LEAP
Manifesto entitled The LEAP Protocol Development
Model.
+-------------------------------|-----------------------------+
| WAP | LEAP |
|-------------------------------|-----------------------------|
|Subject to known patent |Patent-free |
|restrictions | |
|-------------------------------|-----------------------------|
|Self-published by the WAP |Published as Internet RFCs |
|Forum | |
|-------------------------------|-----------------------------|
|Revisions subject to change |All revisions permanently |
|without notice |fixed |
|-------------------------------|-----------------------------|
|Maintained by the WAP Forum |Maintained by open working |
| |groups |
|-------------------------------|-----------------------------|
|Re-invention of existing |Efficiency-optimizing |
|protocols |extensions to existing |
| |protocols |
|-------------------------------|-----------------------------|
|Tailored to mobile phone user |User interface independent |
|interface characteristics | |
|-------------------------------|-----------------------------|
|Inherent security |Imposes no security |
|vulnerability |assumptions |
|-------------------------------|-----------------------------|
|Inconsistent protocol number |Consistent protocol number |
|assignment |assignment |
|-------------------------------|-----------------------------|
|Initial focus: web browsing |Initial focus: messaging |
+-------------------------------|-----------------------------+
Table 1: WAP versus LEAP
4 Comparison of LEAP to WAP
=============================
In The WAP Trap, we enumerated the characteristics
of the WAP specifications that make them wholly
unfit to be the industry standard. These
characteristics are summarized in Table 1, along
with the corresponding characteristics of the LEAP
protocols.
4.1 Patent Restrictions
-------------------------
As noted in The WAP Trap, the WAP specifications
include patented components. Unlike WAP, the LEAP
protocols are entirely patent-free.
4.2 Openness of Publication
-----------------------------
As noted previously, the LEAP protocols are
published as Internet RFCs, ensuring permanent,
unrestricted availability of the protocols. The
WAP specifications, on the other hand, are
self-published by the WAP Forum, and therefore do
not carry the same assurances of unrestricted
availability. The availability and permanence of
the WAP specifications is only as good as that of
the WAP Forum itself.
Furthermore, in order to download any particular
WAP specification, a user must agree to a license
agreement. By contrast, the LEAP protocols may be
downloaded and distributed without any
restrictions.
In addition, the WAP Forum's publishing philosophy
carries no guarantee of stability. As of February
2000, each WAP specification carries on its title
page the disclaimer, ``This document is subject to
change without notice.'' By virtue of the RFC
publication process, on the other hand, individual
revisions of the LEAP protocols are permanently
fixed.
4.3 Openness of Maintenance
-----------------------------
LEAP's open maintenance processes are also in
sharp contrast to WAP. Participation in the
development of the WAP specifications requires
payment of the $27,000 WAP Forum membership fee
(as of February 2000), and takes place entirely
behind closed doors. Unlike WAP, the LEAP
protocols are maintained by public maintenance
organizations in which anyone is free to
participate.
4.4 Technical Deficiencies
----------------------------
The WAP protocols also include numerous technical
deficiencies. For example, WAP is a broad-scope
re-invention of existing protocols. The LEAP
protocols, by contrast, consist of a small number
of independent protocols that complement existing
Internet protocols. Other deficiencies are listed
in Table 1; for a detailed discussion, see The WAP
Trap.
4.5 Initial Focus
-------------------
There are also significant conceptual differences
between LEAP and WAP, of which we will mention two
here. First, LEAP is primarily oriented towards
the mobile messaging (i.e. e-mail) application,
whereas WAP is primarily oriented towards mobile
web browsing. We believe that this represents a
serious misunderstanding of the mobile data
communications industry on the part of the WAP
Forum. Hand-held mobile devices are extremely
well-suited to the e-mail application, whereas
their severe user interface limitations render
them highly ill-suited to web browsing.
Second, LEAP and WAP take very different
approaches to the messaging application. The LEAP
approach, embodied in the EMSD protocol, is a
complete and efficient submission and delivery
model. The WAP approach, on the other hand, is a
mailbox access and selective message retrieval
model.
A consequence of this is that the WAP protocol has
several unresolved issues relating to message
delivery. For example, the WAP protocol does not
support the ``push'' model of message delivery, in
which time-critical messages are actively
delivered to the recipient. The LEAP protocol, by
contrast, fully supports the ``push'' model.
5 Making LEAP Widespread
==========================
Thus far our discussion has been entirely
theoretical; we have demonstrated on paper that
WAP is not viable, and that LEAP has all the
characteristics necessary to be considered a
viable alternative. However this is all academic
until the protocols are implemented as software
and deployed in real world systems.
In order for the LEAP protocols to become widely
used, they must be implemented in the form of
software solutions that are readily available for
deployment by end-users. To this end, we have
created software implementations of the protocols
for most common platforms. Protocol engines have
been implemented in the form of portable code
which has been ported to a variety of platforms.
On the device side, software has been implemented
for pagers and cell-phones; for hand-held PCs and
Palm Pilot (Palm OS, Windows CE, Palm PC); for
Windows 98, Windows 95, and Windows NT; and for
Pine (UNIX, Windows, DOS). On the message center
side, software has been implemented for Solaris,
Linux and NT.
All of this software will be made publicly
available in the form of free software in
open-source format. At present, we have created
the structures necessary to allow ready access and
downloading of the software in binary form.
Foundation libraries of LEAP protocol engines
called the ``Open C Platform (OCP)'' are subject
to GNU Library General Public License and are
available as open-source software.
The software is being made available at
http://www.MailMeAnywhere.org/
We expect to have the ESRO protocol engine
software components subject to the GNU General
Public License available at this location by
September 2000. We expect the availability of the
entire suite of open-source software
implementations described above to be completed by
December 2000.
As noted above, the initial emphasis of LEAP is on
the mobile messaging application. Protocol
engines are only a single component of a bigger
picture; in order to provide complete solutions to
the user it is necessary to integrate these
protocols into other existing pieces of software.
Fully-integrated solutions which combine LEAP with
other open-source and free software packages such
as qmail, sendmail, fetchmail will also be made
available.
We invite those interested in using, enhancing,
porting and integrating this software to join the
relevant mailing lists at
http://www.MailMeAnywhere.org/
We will also initially ``prime the pump'' by
providing free subscriber services through
ByNumber.net and ByName.net. This will provide
initial support for the implementation adoption of
the protocols in end-user devices. Usage of the
protocols among a sufficient number of user
devices will then provide the motivation for usage
among the message center systems.
6 Other Alternatives to WAP
=============================
In this article we have promoted LEAP as one
alternative to WAP. An obvious question is: Are
there any other alternatives?
A traditional source of Internet protocols is the
Internet Engineering Task Force, or IETF. To our
knowledge, however, no protocol specification
which addresses the requirements for efficient
Mobile Messaging can be expected from the IETF in
the near future.
Other traditional sources of protocols are private
industry, and the academic community. However,
thus far a suitable protocol has been forthcoming
from neither of these sources. There is general
consensus within the industry that an alternative
protocol to WAP is required. Apart from LEAP,
however, no such protocol has yet been publicly
proposed.
To the best of our knowledge, therefore, LEAP is
the only viable open and patent-free alternative
to WAP.
7 Summary
===========
All of the basic components that are needed to
launch LEAP are complete, in place, and ready to
go. These components are:
The Protocols Themselves. The protocols are
well-designed, meet all the technical
requirements of the industry, and are
published as RFC-2188 and RFC-2524. The
complete text of the RFCs is available at
http://www.rfc-editor.org.
Freedom from Patents. The protocols have been
declared to the Free Protocols Foundation as
patent-free. For more information see
http://www.FreeProtocols.org.
Open Maintenance Organizations. The protocols are
maintained by open and public organizations at
http://www.esro.org, http://www.emsd.org, and
http://www.LeapForum.org.
Open-Source Software Implementations. These are in
the process of being made available for all
major platforms and end-user devices. For
details see http://www.MailMeAnywhere.org.
Free Subscriber Services. Provided to support
initial deployment of the protocols in
end-user devices. For details see
http://www.ByNumber.net and
http://www.ByName.net.
Together, these components represent a complete
recipe for the success of LEAP. The protocols
themselves are open and immediately available, and
open-source implementations of the protocols are
in the process of being made available as free
software.
The combination of free protocols and open-source
software is something which has enormous power.
It is this combination of factors which has driven
the overwhelming success of other industry
standards such as Linux and Web (HTTP/HTML). We
believe that this same combination of factors will
drive the acceptance of LEAP in the wireless data
communications industry.
Finally, we do not claim that LEAP is technically
ideal -- like all engineering solutions it
includes compromises. What we do claim is that
LEAP is a good solution, and that its processes
have integrity. Where the LEAP protocols fall
short of the industry needs, the open maintenance
processes will provide a mechanism by which they
can evolve into a better solution.
7.1 The LEAP Manifesto
-----------------------
Every aspect of LEAP is described in The LEAP
Manifesto [3], available at
http://www.LeapForum.org/LEAP/Manifesto/roadMap/index.
html. The LEAP Manifesto includes a technical
description of the LEAP protocols themselves, and
a description of all the components required to
encourage their widespread usage. The LEAP
Manifesto consists of the following articles:
Executive Summary. An overview summary of the
entire LEAP Manifesto.
Overview of the LEAP Protocols. A general overview
description of the LEAP protocols.
The LEAP Protocol Development Model. A description
of the processes used to develop the LEAP
protocols, and how and why these processes
differ from the conventional development
process.
EMSD: The LEAP E-Mail Component. A technical
description of EMSD, the e-mail component of
LEAP.
ESRO: A Foundation for the Development of Efficient Protocols.
A technical description of ESRO, the transport
mechanism component of LEAP.
Efficiency of EMSD. A technical paper analyzing
the efficiency characteristics of EMSD and
comparing its efficiency to other e-mail
protocols.
EMSD on Windows CE. A technical paper describing
the architecture and implementation of EMSD on
Windows CE devices.
EMSD on Palm OS. A technical paper describing the
architecture and implementation of EMSD on
Palm OS devices.
A Brief History of LEAP. A summary of the major
events in the evolution of the LEAP protocols.
The Future of LEAP. A description of the planned
future development of LEAP, including
descriptions of several LEAP-based products
and services which are currently under
development.
The WAP Trap. A detailed criticism of a set of
specifications called the Wireless Application
Protocol, or WAP. This article demonstrates
that WAP is entirely inappropriate to play the
role of a Mobile Messaging industry standard.
LEAP: One Alternative to WAP. A point-by-point
comparison of the LEAP protocols to the WAP
specifications. This article compares and
contrasts LEAP with WAP, and demonstrates that
LEAP has all the desirable characteristics of
an industry standard protocol that WAP lacks.
Operation WhiteBerry. A description of how all the
capabilities of the closed RIM BlackBerry
mobile messaging solution can be duplicated
using existing software implementations of
LEAP, and existing off-the-shelf hardware
components.
Strategy for Making LEAP Widespread. A description
of our strategy for encouraging widespread
usage of the LEAP protocols, including the
distribution of open-source software
implementations of the protocols, and the
availability of free subscriber services.
Trying Out LEAP. A step-by-step, hands-on
demonstration of how the LEAP protocols can be
used to turn any Windows CE device into a
fully functional Mobile Messaging device.
Lessons from History: Comparitive Case Studies.
An analysis of the factors which lead to the
success or failure of protocols, including
discussions of several historical case
studies.
The Mobile Messaging Industry. An overview of the
Mobile Messaging industry, and a description
of the essential factors that are required for
its long term success and growth.
References
==========
[1] M. Banan. Neda's Efficient Mail Submission and
Delivery (EMSD) Protocol Specification Version
1.3. Request for Comments (Informational)
2524, Neda Communications, Inc., February
1999. Online document is available at
ftp://ftp.isi.edu/in-notes/rfc2524.txt.
[2] M. Banan, J. Cheng, and M. Taylor. AT&T/Neda's
Efficient Short Remote Operations (ESRO)
Protocol Specification Version 1.2. Request
for Comments (Informational) 2188, Neda
Communications, Inc., September 1997. Online
document is available at
ftp://ftp.isi.edu/in-notes/rfc2188.txt.
[3] Mohsen Banan. Lightweight & Efficient
Application Protocol (LEAP) Manifesto. FPF
Published Document 108-101-01, Free Protocols
Foundation, Bellevue, WA, January 2000. Online
document is available at
http://www.freeprotocols.org/pubs/biblio/108-101-01/index.html.
[4] Mohsen Banan. The WAP Trap. FPF Published
Document 108-102-01, Free Protocols
Foundation, Bellevue, WA, January 2000. Online
document is available at
http://www.freeprotocols.org/pubs/biblio/108-102-01/index.html.