IndexShort Message Service / SMS IntroductionPopular SMS Protocol – SMPPSome Components & Open Sources
Short Message Service / SMS Introduction Introducing to SMS Messaging Some properties that made SMS popular Example Applications of SMS Messaging What is an SMSC ? Some basic concepts of SMS Technology Intra-operator, Inter-operator, International-operator SMS Messages What is an SMS Gateway ? Some other stuffs
Introducing to SMS Messaging SMS stands for Short Message Service. It is a technology that enables the sending and receiving of messages between mobile phones. SMS first appeared in Europe in 1992 (GSM at the beginning & ported to other tech. as CDMA & TDMA). The GSM and SMS standards were originally developed by ETSI (European Telecommunications Standards Institute). Now the 3GPP (Third Generation Partnership Project) is responsible for the development and maintenance of the GSM and SMS standard.
Introducing to SMS Messaging The data that can be held by an SMS message is very limited - 1 SMS = at most 140 bytes (1120 bits): 160 characters if 7-bit char encoding (Eg: Latin/English) 70 characters if 16-bit Unicode UCS2 char encoding (Chinese/ Vietnamese/ ...) SMS messages can also carry binary data (ringtones, pictures, operator logos, wallpapers, animations, business cards (e.g. VCards) and WAP configurations). SMS is that it is supported by 100% GSM mobile phones.
Introducing to SMS Messaging Concatenated SMS Messages/ Long SMS Messages can contain more than 160 English characters. It works like this: User sends SMS, its broken down into smaller parts These parts are sent as a single message. All SMS reach destination & mobile combines all those ones into 1 long SMS. Mobile must support this one.
Introducing to SMS Messaging EMS (Enhanced Messaging Service) to support rich media (pictures, animations, melodies) it is an application-level extension of SMS. the formatting of the text inside an EMS message is changeable (font size, bold, italic, ...) EMS is not supported by all mobile devices. To a EMS-enabled mobile, EMS is maybe implemented with a subset of the features defined in the EMS spec.
Some Properties of SMSSMS Messages can be Sent and Read at Any TimeSMS Messages can be Sent to an Offline Mobile PhoneSMS Messaging is Less Disturbing While You can Still Stayin TouchSMS Messages are Supported by 100% GSM Mobile Phonesand They can be Exchanged between Different WirelessCarriersSMS is a Suitable Technology for Wireless Applications toBuild on (100% phones, Rich content, Reversebilling)
Example Applications of SMS Messaging Person-to-Person Text Messaging (chat) Provision of Information & Stock market Alerts (DowFeeds, News, CitiSearch, ...) Downloading (Ringtone, Wallpaper, ...) Promotion/Marketing/SMS Newsletter (ABVending, ...) Entertainment (Game, Music Recognition, ...) Quiz (Clearasil, ECGames, ...) Banking activities (m-Payment, m-Banking, ...) Alerts & Notifications (TicketMaster, ...) Email, Fax, Voice messaging notifications E-Commerce & Credit card transaction alerts Remote system monitoring ...
What is an SMSC ?An SMS center (SMSC) is responsible for handling the SMSoperations of a wireless network.SMS will reach SMSC first (often locate inside wirelesssystem of operator but maybe has 3rd-party outside).An SMS message may need to pass through more thanone network entity (e.g. SMSC and SMS gateway)The main duty of an SMSC is to route SMS messages andregulate the process. SMSC will store the message ifmobile is unavailable.We must know the address of the wireless networkoperators SMSC to use SMS messaging with mobile phone(typically its International Number of phone).This address is pre-set in the SIM card but maybewe can change it.
Basic Concepts of SMS Technology Carrier / Operator. MO (Mobile Originated) / MT (Mobile Terminated). Short Code / Long Code. Validity Period of an SMS Message. Message Status Reports (set a flag in the SMS to notify the SMS that we want a status report about the delivery of this SMS). Default is turned-off on mobiles. Message Submission Reports. Message Delivery Reports.
Basic Concepts of SMS Technology Messages transfer between 2 SME (SM Entity)
Basic Concepts of SMS Technology Messages transfer
Intra-operator SMS MessagesIf both sender and receiver are using the mobile phoneservice of the same wireless network operator, thetransmission of an SMS message will involve only onewireless network operator. This SMS message is called anintra-operator SMS message.The cost for sending an intra-operator SMS message froma mobile phone is lower than other types (sometimestotally free).
Inter-operator SMS MessagesSender and receiver are using the mobile phone service ofwireless network operator A & B respectively. Thetransmission of an SMS message from you to your friendinvolves two wireless networks. This SMS message iscalled an inter-operator SMS message.Typically, the cost for sending an inter-operator SMS froma mobile is higher than the situation intra-operator SMS.The transmission involves one or more SMS centers.
Inter-operator SMS Messages1st way: Signaling interconnections are set up between twowireless networks. When the originator SMSC receives aninter-operator SMS message, it gets the routinginformation from the recipient wireless network & deliversthe SMS message to the recipient mobile phone directly.The following figure illustrates the transmission process:Using 1 SMSC in this case = the same technology
Inter-operator SMS Messages2nd way: to solve the different technologies problembetween 2 networks (GSM & CDMA for example) or 2SMSCs talk to each other via SMS Gateway:
International SMS MessagesInter-operator SMS messages can be further divided intotwo categories: • local inter-operator SMS messages (the same country). • international inter-operator SMS messages (sender & receiver are in 2 different countries).The cost is most expensive than others.The interoperability of SMS messaging among localnetworks & international networks made SMS popular &success of SMS worldwide.
What is an SMS Gateway?Problem of SMS messaging: SMSCs developed by differentcompanies use their own communication protocol andmost of these protocols are proprietary. • For example, Nokia - CIMD; CMG - EMI.Solution: an SMS gateway is placed between two SMSCs.(The SMS gateway acts as a relay between the twoSMSCs).
What is an SMS Gateway?To developers: its very useful in the case our applicationsmust make connections directly to SMSCs developed withmany different protocols --> complexity & dev. time ++! App. connects to SMCSs without SMS Gateway
What is an SMS Gateway?An SMS text messaging application connects to SMSCsthrough an SMS gateway.
What is an SMS Gateway?Another way to send and receive SMS text messages on acomputer is to use a mobile phone or GSM/GPRS modem.An application connects to a pool of mobile phones orGSM/GPRS modems through an SMS gateway.
Short Message Peer to Peer (SMPP) The SMPP protocol is an open, industry standard protocoldesigned to provide a flexible data communications interfacefor transfer of short message data between a MessageCenter, such as a SMSC, GSM Unstructured SupplementaryServices Data (USSD) Server or other type of MessageCenter and a SMS application system, such as a WAP ProxyServer, EMail Gateway or other Messaging Gateway. SMPP Release v3.4 supports Digital Cellular Networktechnologies including: • GSM • IS-95 (CDMA) • ANSI-136 (TDMA) • iDEN
Short Message Peer to Peer (SMPP) SMPP supports a full featured set of two-way messagingfunctions such as: Transmit messages from an ESME to single or multiple destinations via the SMSC. An ESME may receive messages via the SMSC from other SME’s (e.g. Mobile stations). Query the status of a short message stored on the SMSC. Cancel or replace a short message stored on the SMSC. Send a registered short message (for which a ‘delivery receipt’ will be returned by the SMSC to the message originator). Schedule the message delivery date and time.
Short Message Peer to Peer (SMPP)(... continue ... ) Select the message mode, i.e. datagram or store and forward. Set the delivery priority of the short message. Define the data coding type of the short message. Set the short message validity period. Associate a service type with each message e.g. voice mail notification.
Short Message Peer to Peer (SMPP)Context of SMPP in a Mobile Network
SMPP – Overview SMPP is an application layer protocol. ESMEs: External Short Message Entities. ESME is non-mobile entities that submit/receive SMS fromSMSC. The SMPP protocol defines: • a set of operations for the exchange of short messages between an ESME and an SMSC. • the data that an ESME application must exchange with an SMSC during SMPP operations.
SMPP – Protocol Definition Based on the exchange of request and response protocoldata units (PDUs) over an underlying TCP/IP or X.25 networkconnection. The SMPP protocol defines: • a set of operations and associated Protocol Data Units (PDUs) for the exchange of SMS between an ESME and an SMSC. • the data that an ESME application can exchange with an SMSC during SMPP operations. Every SMPP operation must consist of a request PDU andassociated response PDU except alert_notification PDU
SMPP – Protocol DefinitionThe exchange messages maybe are categorised as below: • Transmitter: messages sent from the ESME to the SMSC. • Receiver: messages sent from the SMSC to the ESME. • Transceiver: from the ESME to the SMSC and from the SMSC to the ESME.
SMPP – Session Descriptioninitiated by the ESME: • first establishing a network connection with the SMSC. • then issuing an SMPP Bind request to open an SMPP session for sending and/or receiving messages.
SMPP – Session Description The SMPP session maybe defined in terms of the followingpossible states: • OPEN (Connected and Bind Pending) • BOUND_TX (ESME issues a bind_transmitter PDU – send SMS, replace, query, or cancel) • BOUND_RX (ESME issues a bind_receiver PDU – receive SMS, delivery receipt, ...) • BOUND_TRX (ESME issues a bind_transceiver PDU – included complete set of operations from TX & RX) • CLOSED (unbound and disconnected – maybe come from 1 of 2 sides) • OUTBIND is to allow the SMSC signal an ESME to originate a bind_receiver request to the SMSC
SMPP SMS sent from ESME to SMSC SMS PDUs via TX o TRX session: • submit_sm • data_sm Other related operations (base on message Identifierreturned by SMSC in the message ACK): • query_sm • cancel_sm • replace_sm
SMPP Response from SMSC to ESME SMPP PDU Response for a message submission includes amessage identifier & a status to inform ESME whether themessage is valid or invalid: • submit_sm_resp • data_sm_resp • query_sm_resp • cancel_sm_resp • replace_sm_resp
SMPP SMS sent from SMSC to ESME ESME must be connected to the SMSC as an ESME Receiveror as an ESME Transceiver. Example: • Email gateway got messages from mobile stations. • SMSC may also sends a “delivery receipt” to ESME. PDUs (required response PDU from ESME exceptalert_notification PDU): • deliver_sm • data_sm • deliver_sm_resp • data_sm_resp
SMPP Error Handling & Timers The receiving entity must return the associated SMPPresponse PDU to an SMPP request PDU exceptalert_notification PDU. Error found in request PDU: return a response withappropriate error code inserted in command_status field ofresponse PDU header. If PDU header is error, returns a generic_nak PDU. Recommend about timers: • An SMPP session initiation timer • An SMPP session timer (enquire_link) • An SMPP inactivity timer • An SMPP transaction timer
SMPP Message Modes SMSC allows ESME to select the SMSC message deliverymechanism: • Store and Forward (stored at SMSC data store & forward to recipient SME – submit_sm, data_sm) • Datagram (emulates the datagram paradigm of UDP – high msg. Throughput without secure storage & retry guarantee – data_sm using esm_class parameter, also support submit_sm) • Transaction Mode (allow ESME receive a form of delivery ACK within response PDU – only data_sm with esm_class parameter)
SMPP Message Types Message type is defined in the esm_class parameter ofsubmit_sm, data_sm, and deliver_sm. Types are: • SMSC Delivery Receipt (is carried as the user data payload deliver_sm or data_sm operation) • Intermediate Notification (intermediate status of a message delivery attempt) • SME Delivery Acknowledge (an indication from the recipient SME that the user has read the short message) • SME Manual/ User Acknowledgement • Conversation Abort
DocumentsSMPP – SMS Forum (all versions – V3.4/ V5.0...) • http://smsforum.net/SMPP_v3_4_Issue1_2.pdf at Local documents belowLocal documents • yp-server_Documents_Ebooks_ProtocolsNokia Forum http://forum.nokia.com/main/resources/technologies/messaging/short_messaging/documents.html
Free/Non-Free SMS GatewaysOne high-quality free SMS gateway software package isKannel, which is written in the C programming language • It can handle connections to SMSCs, mobile phones and GSM/GPRS modems • It has an HTTP / HTTPS interface for the sending and receiving of SMS messages • Url: http://www.kannel.org/Tambur Messaging Gateway is an open source SMS/MMSmessaging gateway platform • Url: http://www.tambur.org/NowSMS: Commercial SMS Gateway • Url: http://www.nowsms.com/ http://www.nowsms.com