White Paper

Short Message Service Gateway July 2005

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SMS Gateway White Paper

Copyright © 2005 IMI Software Ltd. All Rights Reserved.

IMImobile, A Division of IMI Software Ltd

Though every care has been taken to ensure the accuracy of this document, IMI Software Ltd. cannot accept

responsibility for any errors or omissions or for any loss occasioned to any person, whether legal or natural, from

acting, or refraining from action, as a result of the information contained herein. Information in this document is

subject to change at any time without obligation to notify any person of such changes.

IMI Software Ltd. may have patents or patent pending applications, trademarks copyrights or other intellectual

property rights covering subject matter in this document. The furnishing of this document does not give the

recipient or reader any license to these patents, trademarks copyrights or other intellectual property rights.

No part of this document may be communicated, distributed, reproduced or transmitted in any form or by any

means, electronic or mechanical or otherwise, for any purpose, without the prior written permission of IMI

Software Ltd.

The document is subject to revision without further notice.

All brand names and product names mentioned in this document are trademarks or registered trademarks of their

respective owners.

Asia

Kautilya, 6-3-652,

Somajiguda,

Hyderabad – 500 082, India.

Phone: +91-40-23310233

Fax: +91-40-23311643

Europe

33 Glasshouse Street

London, W1B 5DG, UK

Phone: +44(0) 20 7851 7780

Fax: +44(0) 20 7851 7770

www.imimobile.com

sales@imimobile.com

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Table Of Contents

Executive summary........................................4 SMS –Short message service..............................4 Need for SMS gateway.....................................4 Features and functionality...............................5 ESME ..........................................................5 Router......................................................... 5 HTTP Box ..................................................... 6 HTTP server .................................................. 6 SMS Encoder.................................................. 6 Log Server and Database .................................. 6 Admin GUI .................................................... 6 Performance ................................................6 Why IMImobile? .............................................8 Why IMImobile? .............................................8 Advantages ................................................... 8 Applications .................................................. 8 Future of SMS ...............................................8 Conclusion ...................................................9 Glossary .................................................... 10

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Executive summary Short message service (SMS) is a globally accepted wireless service that enables the transmission of alphanumeric messages between mobile users and external systems such as electronic mail, paging, and voice mail systems. SMS is based on standards defined by ETSI and 3GPP. Messaging is handled by an SMSC (Short Message Service Center) that is hosted within the Operator network. SMS is an easy to use service that has become extremely popular with billions of messages being handled every month. The main categories of SMS messages are: • Peer to Peer messaging – handled by SMSC in the

Operator domain • Value added services between a mobile phone

and applications – handled by SMS Gateway – Operators and Service Providers

An SMS Gateway provides an open interface between the SMSC in the Operator network to Applications in the IT domain. Some of the advantages of using an SMS gateway are: • Open interface on HTTP - Standardized by Parlay

X as a web service • Configure multiple application providers • Connect to multiple SMSC and manage multiple

Short codes • Configure keywords / extension codes to

applications • Manage traffic and quotas • Promotions and Campaigns • Rich content delivery through WAP SI on SMS Value added services on SMS have become very popular due to Interactive TV shows, Rich content access and delivery (Ringtones, Images), promotions, campaigns and a whole range of services. This requires operators and service providers to be able to handle large traffic volumes, provision new services rapidly, add new SMSC to cater to load or new regions – all without affecting existing services in a reliable and flexible manner. IMImobile SMS gateway is a scalable, and high performance messaging system that can connect to multiple SMSC and a large number of applications. It is scalable to support 5 million busy hour messages on a single system, and is deployed live on a number of Operator networks for Operators and Service providers.

SMS –Short message service Short message service (SMS) is a service available on most digital mobile phones that permits the sending of short messages also called as text messages between mobile phones and other handheld devices. SMS was originally designed as part of the GSM digital mobile phone standard, but is now available on a wide range of networks, including 3G networks. SMS messages can comprise of words or numbers of up to 160 characters in length. Out-of-band packet delivery and low-bandwidth message transfer characterize SMS. Non-text based (binary format) characters can also be supported, and are essential for Unicode and Rich Content services. SMS is based on store-and-forward technology. Messages are sent to an SMSC located at Operator’s side, held for the intended recipient, and then sent from the SMSC to the recipient's mobile phone. SMS is capable of confirming whether a message has been delivered, though it is up to the individual carrier to implement this capability. The confirmation function is handled by the SMSC. A record of 15 billion sms was sent globally in 2000 ,which increased to 200 billion in 2001 and expected to be two trillion in 2008. Need for SMS gateway SMS Applications can be delivered to users by interfacing them to an SMSC, which is the central component in an SMS network. SMS gateway is necessary for the following reasons: • Compatibility - Supports inter networking

amongst various SMSCs implemented by various vendors

• Conversion of SMS protocols such as SMPP/CIMD/UDP to HTTP format

• Handles and control of large traffic • Keeps track of the records such as user details,

time stamp billing etc. • Supports APIs for easy plug in of applications Fig (1) shows the connection of SMS gateway to SMSC and external applications.

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Fig (1) Interface of SMS gateway to SMSC and

external application

Features and functionality This section describes the features and functionality of SMS gateway that have been provided as per the 3GPP standards. Fig (2) shows various modules of SMS gateway and their interface with the external applications.

Fig (2) Architecture of SMS gateway ESME The Gateway can connect to multiple SMSC concurrently, and an ESME (External Short Messaging Entity) client handles the connection. An ESME client is identified by the SMSC to which the connection is made, and represents a single connection to a SMSC. The ESME client receives MO messages from the operator SMSC and submits messages back to the SMSC for MT delivery to the user handset. The main functions of the ESME client are: • Bi-directional connection to a SMSC • Support SMS protocols (SMPPv3.2/CIMD2/UCP),

SS7 protocols

The Gateway supports multiple ESME clients. Each ESME client forms part of a SMS message channel that comprises of the ESME client, Router and a HTTP box. For a new connection, the gateway creates a new message channel, and handles the connection, binding and reconnection settings, to ensure that the link is always maintained. In case a specific link is down, the corresponding ESME client automatically sends a bind request, till success. The status of the ESME connections can be seen visually on the control center. Router The SMS Gateway supports multiple routers unlike MMS gateway. A single router can be attached to a specific ESME or shared by a set of ESME. It performs routing in a number of different ways, depending on configuration options. Routing options for each application server and each ESME can be configured separately, to allow a flexible and scalable routing option. SMS Gateway Router has the following properties: • Router ID - For identifying and linking the router. • Default URL – Defines parameters such as MSISDN

number, message, keyword, timestamp. These are parameterized and can be changed at runtime.

• Variable parameters - Additional parameters in USIM applications, such as TAR, CNTR, PCNTR, Status code, RC/CC/Ds, Application response data

• Retry count – Retry delivery of the message • Timeout -To handle failures/delay in application

response • Keywords – ASCII and Unicode • Extension codes - for linking request and

response streams • Message split limit – Long messages are slit

automatically into 140 octet units Some of the functions of router are as follows:

• Pull Routing for MO messages – Routes incoming SMS messages sent from a mobile phone or another application server. Routing can be based on URL, Text Keywords, Binary Messages, subject line

• Custom routing options –Router implements a

plug in routing option, that can use a shared/dynamic library to implement customized routing options. For example numeric range, partial match, multiple word matches etc.

• URL Definition- URL can be expressed in terms of

constant and variable parameters. A variable parameter is defined as $(name), where “name” is a list of reserved words that have a predefined

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meaning. Thus, ph=$(msisdn) would replace the actual MSISDN number, and the corresponding value will be ph=919xxxxxxxxx based on the request

HTTP Box An application represents an external application that is accessible over HTTP. This could be an intranet or Internet application. Once the router identifies the target URL for the request, the message object is pushed into the HTTP box queue for processing. The HTTP supports asynchronous requests to applications on HTTP /1.0 or higher. The number of concurrent requests can be configured on the box, which will then generate the request based on the URL generated by the router. HTTP server The gateway has an internal high performance multi threaded HTTP server, developed by IMImobile for it’s SMS Gateway, MMSC and other server based products. The server hosts C++ applications, both as statically linked libraries and dynamic libraries. Push messaging for text and binary SMS is implemented as applications. Custom applications for handling specific requirements can be implemented on the server, such as encryption, byte code compilers for USIM applications etc. SMS Content • Ringtones – RTTTL, RTX, iMelody • Logos – GIF, BMP • Picture Messages • Animations • CLI Icons • vCard (Nokia) • vCalendar (Nokia) • OTA settings for WAP/MMS • Generic Binary content

MMS Content as WAP push • Polyphonic Ringtones • Screen savers • Images • Video SMS Encoder The SMS Gateway supports text and binary encoding as per 3GPP and GSM standards, that allows third party content providers to use the SMS Gateway in a consistent and uniform manner for a whole range of content. Generic binary content can be submitted to the gateway, which is then delivered, by the gateway after splitting into concatenated messages if required.

Applications can transmit data in several methods such as text messages, Binary message in hex, Individual UDH, IEI and UD, Customized API similar to the IMI SMS WAP OTA Message API above will allow messages to be generated, based on command parameters. Thus in the specific case of USIM applications, a plug in module can be developed that can be used to generate the Command packet based on individual parameter values. The same applies to Response packets that can be parsed as per the data. Log Server and Database The Log Server provides a generic IP based interface that is used to support dynamic logging, as well as to provide a query interface to Databases. The server has its own internal queuing that provides a buffer for incoming requests. The server supports MS SQL 2000. In all cases, the database can run on the same system or be separated and can be accessed over UDP/IP. The server monitors a specific port, which can be configured. Admin GUI The Graphical user interface provides full control over the various components of the Gateway including start/stop configure ESME clients, Applications, view logs, reports and alarms. The GUI is developed as a web-based interface, and is implemented using Java servlets, hosted on a Tomcat Server. The GUI can again be hosted on the same system or a separate system. Performance Performance of SMS gateway depends on the concurrent users, number of EMSE, HTTP servers and number of processors. Using the following methods can easily enhance the performance of SMS gateway: • Additional ESMEs • Additional processors/RAM for increase in

concurrent connections • Additional HTTP servers deployed on the

network, which connects to the same database server and ESME

Fig (3) shows the stress test for IMImobile SMS gateway with 32 concurrent SMPP servers. The test system is based on Intel P4, single processor - 2.8 GHz speed and 512 MB RAM. It can be observed that 2000 messages per second are supported by this gateway. The recommended hardware is a dual XEON processor system with 4GB RAM and will have at least twice this capacity.

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Fig (3) SM

S gateway stress test

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Why IMImobile? IMImobile SMS gateway offers a cost effective approach towards quickly and easily implementing and deploying short Messaging Services (SMS). IMImobile SMS gateway is a scalable and flexible platform. Advantages • Supports multiple ESME and multiple application

clients • Allows new protocols to be introduced at runtime

with considerable ease • Capable of being configured entirely on HTTP

thus allowing remote configuration • Supports popular protocols such as SMPP / CIMD2

/ HTTP • Capable of handling 2000 messages (SMS) per second • Supports multiple SMSC and Content Server connections

over the Internet • Automatically generates extensive logs to easily

track problems • Supports transfer of popular SMS services such as

ring-tones (SMART and EMS), picture messages, logos, WAP push messages, Over the Air (OTA) settings, WAP settings and much more

• Extensive keyword and extension code support • Session handling for user last command Applications IMImobile SMS gateway supports several applications for subscribers, operators and service providers. Some of them are listed below: For users • Download and dedicate ring - tones, picture

messages and operator logos • Subscribe and get updated of happening events

around the world, news and other interesting information

• Play exciting SMS games and contests • Provision of value-added services such as e-mail,

voice mail, and fax mail integration • SMS messaging is a discreet way of contacting

people when they do not want to be disturbed by phone calls

• E-mail message arrivals can be notified to a SMS device

For Service providers and operators • Hiding the complexity of various SMSC protocols

and their divergent functionalities • Producing billing solutions for export to billing

systems • Extensive APIs to support service development in

any environment • Supports bulk Messaging • Load balancer to control traffic load

Future of SMS Demand for SMS is increasing everyday. Research has predicted that two trillion messages would be sent each year by 2008. SMS has a bright future filled with new technologies and methods for simplifying lifestyles. Research is been carried out in order to improve the present services of text messages. New technologies include services such as mobile phones that automatically convert speech into text. Rather than rely on cramming words in tiny fonts onto a small screen comprising of 160 characters limit, instead users can just dictate. Other services could be as follows: • Sender sends a SMS and it is translated to voice • Way of making the SMS sound just like the other

person • Real time applications • Send a text/SMS message to a landline and the

phone will ring in residence. On answer your SMS message is read by a person

• TV Chat – A phone-to-TV SMS service where end-users can have their messages flashed up on the TV screen. Benefits are as follows: o Easy and quick start-up o Multiple revenue streams (SMS-Premium -

Advertising - Sponsoring) o Real-time statistics o Modular, scaleable technology

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Conclusion SMS (Short Message service) is the ability to send and receive text messages to and from mobile phones. Number of SMS sent globally in 2000 was fifteen billion and expected to be two trillion by 2008.This indicates a large demand for SMS. The SMS gateway is a scalable and high performance messaging platform system that can connect to multiple SMSC and large number of applications. It is scalable to support 5 million busy hour messages on a single system. IMImobile SMS gateway is a software system and is deployed for high traffic and connects to large number of Operators and Service providers in India and Middle East. Gateway is composed of various modules integrated on a single platform. The main functions of the SMS gateway are: • Multi-vendor SMSC compatibility. • Supports various protocols such as

CIMD/UDP/SMPP. • Load balancing to control the traffic. • Support for several APIs for various applications. • Bulk messaging. • Supports Peer-to Peer messaging and application-

to-peer.

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Glossary 3G - Third generation API – Application programming interface BMP - Bitmap CIMD - Computer Interface for Message Distribution DCS - Data coding scheme ESME - External Short Messaging Entity GIF - Graphic Image File Format GSM - Global system for mobile communication HTTP - Hypertext Transfer Protocol IEI - Information Element Identifier PDU - Protocol Data Unit RTTTL - Ringing Tones Text Transfer Language SMPP - Short messaging Peer-to-Peer Protocol SMS - Short message service SMSC - Short message service center UD - User Data UDH - User Data Header