WAPA standard for delivery of information, data

and services to both enterprise and consumer users over wireless networks.

Consists of components Network transport protocols Security capabilities An application environment – browser ML, scripting

and telephonyA modular architecture – which allows

Variety of physical implementations Deployment configurations Integration points with existing web and

information services

Origins of WAP Many successes with No Success

Companies designed technologies to deliver wireless data to mobile but none were able to form a standard.

Analog Modem Technologies Supports analog data communications – 4800 to 9600 bps –

effective throughput varies based on signal strength and quality Eg. Enhanced Throughput Cellular (ETC) Technology

Developed by AT & T Paradyne , 1994 ETC equipped Cellular modems operate on the physical and link layer

protocols. Reduces signal transmission by 6 dB – to improve reliability of data

transmission over a wireless connection that is optimized for voice traffic.

Monitors network and dynamically adjusts the transmission speed every five seconds

Transmits small, 32-byte chunks to reduce retransmission time and improve throughput

Similar techs: EC2 (Enhanced Control Cellular) – Motorola, Enhanced Cellular - Microcom

Origins of WAP – contd…Wireless Middleware Solutions

Extend the transport protocols to improve throughput, reliability or user experience.

Secureway Wireless Gateway (Artour) – IBMSoftware in client and server transparently manage

the use of air link beneath any standard TCP/IP application.

Compressing the data encrypting the packets shutting down the cellular link during inactivityFast reconnectionDelayed acknowledgementsApplication middleware: provides caching and data

reduction capabilities

ExpressQ – NetTech Systems (now BroadBeam)Provides asynchronous messagingPushEncryptionRoaming capabilities on a variety of network and

devicesIncludes a developer’s kit for building applications

Handheld Device Markup Language (HDML) and Handheld Device Transport Protocol (HDTP) – Unwired Planet (now Phone.com) – It includes:A micro-browser Optimized protocol stack for supporting web access

from mobile phonesContent written in HDML and sent to gateway for

encoding and then transmitted

AirMobile – MotorolaProvides optimized access to Lotus Notes and

cc:Mail over wireless networksNarrowband Sockets (NBS) - Nokia and Intel

Provides optimized data transport services for UDP over circuit-switched data and GSM SMS

Supports both delivery of notifications and pushed contents

Now part of Nokia Smart Messaging Platform

Each of these middlewares have achieved some success within particular markets and

industries, but none of them were mass deployed for Mobile Internet

Data-Optimized Networks Wireless networks that support wireless data CDPD

Cellular Digital Packet Data Transmits in idle space within an analog voice network. Effective data throughputs 9.6 to 14.4 Kbps. Network latency approx. 1 sec Coverage – throughout United States and Canada

ARDIS Motorola and IBM Packet network Throughput approx. 2.4 Kbps Network latency 4 to 10 seconds Coverage – major US metropolitan markets

RAM Mobile Data RAM and BellSouth Packet network Effective data throughputs approx 4 Kbps. Network latency 4 to 8 secs The network is used to support Palm.net service offered by Palm

Computing

Data-Optimized Networks (DONs)Ricochet

MetricomPacket network – uses low power base stations

placed atop light polesThroughput upto 128 KbpsNetwork latency 1 secLimited Coverage – in campus or corporate env

Commonalities in these DONsLimited coverageSpecial radios requiredHigh per-packet costsSo market penetration limited to specialized

vertical application like public safety industries – not for mass consumer market

Need for a Mobile Internet StandardWhy all the above efforts failed?

Content and application developers reluctant to support as they didn’t have mass consumer market

Handset manufacturers reluctant to build device unless sufficient number of network operators and service providers were willing to market and distribute those handsets

s/w and h/w providers- didn’t find enough sales volume to recover development costs itself

n/w and service providers didn’t want to get locked into a single infrastructure vendor , with not enough set of services and quality handsets

Need for a Mobile Internet Standard

Need for a Mobile Internet StandardWhy a single standard needed?

Content and application developers develop content in a single format which can be delivered over all networks and to all phones

s/w , h/w and tools vendors – develop technologies which will be useful to a broad set of people

Handset manufacturers can rationalize their product line and sell the handsets through network operators

Network operators would be assured on an open, competitive market for handsets, infrastructure, applications and services

Initiation of WAP standardAT & T Wireless Services (AWS) sought to develop a

wireless data infrastructure that was supported by multiple handset manufacturers.

AWS hosted a meeting in Seattle, Washington – calling people from Ericsson, Motorola, Nokia and Phone.com.

They announced a joint effort – WAP on 26th June ’97WAP Forum – Board of Directors – Representatives of

the 4 companies“The initiative is aimed at aligning the companies efforts

to bring advanced applications and Internet content to digital mobile phones. This alignment will result in numerous benefits, among them providing operators differentiation and new business opportunities. In addition, developers of applications and content will be aided, since a single protocol and markup language will work with any vendor’s compatible handsets”

Initiation of WAP standardThe 4 companies promised to publish a public

standard by september 97. Other few companies also joined in two weeks.

They decided that WAP standard would incorporate 3 existing technologiesHDML – Phone.com’s – would be the common

markup languageNBS – Nokia – would become the optimized

transport protocol and HDTP – Phone.com’s would be the optimized session protocol

Intelligent Terminal Transfer Protocol (ITTP) – Ericsson would provide foundation for the telephony application services

Initiation of WAP standardThroughout summer and fall of 97, they tried

to integrate these technologies into a single standard – very complex

All the 4 companies didn’t want to develop a standard which would benefit any one of them at the other’s expense.

So, by september 97, they were able to publish only a WAP architecture document.

Initiation of WAP standardKey issues faced during the specification design

processShould the standard be layered?

Tightly integrated stack – greater n/w optimization, efficient implementation, but complex to integrate the core technologies

Layered approach – allows partial implementations of the standard, can provide APIs at each layer, better segmentation of design responsibilities

Resolution: WAP Forum’s Directors decided, the WAP will be layered,

but implementer can merge layers to provide smaller implementations

Adv: allowed for purity and manageability of design, supported efficient implementations

Disadv: designers could not define standard interlayer APIs

Initiation of WAP standardShould IR-OBEX or HDTP be used as the session

layer?The IrDA (Infrared Data Association) – developed a

session-layer protocol – IrOBEX – binary protocolSupports both push and pull semantics for

accessing dataHTTP-like semantics for Wireless devicesMet many needs of WAP. But not enough to run

over a wide range of wireless networksResolution:

WAP included an new protocol stack – which borrowed ideas from both NBS and HDTP but differed significantly from both

Initiation of WAP standardHow should connection-oriented and

connectionless sessions be supported?Fig (next slide) – HDTP rested on optional security

layer which in turn was on NBS – conflicted with each other.

Redundancy was there – both provided data reliability.

NBS – offered both connctn-oriented and connectnless abstraction

So security layer was forced to support bothHDTP had to provide 4 configurations

Secure connection Insecure connection Secure datagram Insecure datagram

Initiation of WAP standard Security layer ran on top of a datagram layer – so susceptible

to attack from intruder Resolution: Resolved in two stages

(1) During fall of 97 all the three protocols were redesigned HDTP – Wireless Session Protocol (WSP)– similar to

HTTP Security layer – Wireless Transport Layer Security

(WTLS) NBS – Wireless Transport Protocol (WTP) - – reliable

datagram, request-response transactions. (2) During first quarter of 98, WTLS protocol was moved

beneath WTP – to enable only secure datagrams By early 98, first version of WAP standard was nearing

completion.