SMSC Call flows

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SMS Call flows, MAP messages

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SMS & SMSCPresented By:Vikas MiyaSMS OverviewSMS stands for Short Message ServiceSMS is the ability to send and receive short alphanumeric messages to and from mobile telephones.SMS works on store and forward methodBesides text, SMS messages can also carry binary data. It is possible to send ringtones, pictures, operator logos, wallpapers, animations, business cards and WAP configurations to a mobile phone with SMS messages.

SMS OverviewOne SMS message can contain at most 140 bytes (1120 bits) of data, so one SMS message can contain up to:160 characters if 7-bit character encoding is used (suitable for encoding Latin characters like English alphabets.)70 characters if 16-bit Unicode UCS2 character encoding is used (SMS text messages containing non-Latin characters like Chinese)SMS text messaging supports languages internationally lie Arabic, Chinese, Japanese and Korean.

Concatenated/Long SMSOne SMS message can only carry a very limited amount of data. To overcome this drawback, an extension called concatenated SMS A concatenated SMS text message can contain more than 160 English characters.The sender's mobile phone breaks down a long message into smaller parts and sends each of them as a single SMS message.The recipient mobile phone will combine them back to one long message.SMSC OverviewSMSC stands for Short message service centerSMSC is a network element in the mobile telephone network which delivers short messages (SMS)SMSC works on store and forward principle i.e. when a user sends a text message to another user, the message gets stored in the SMSC which delivers it to the destination user when destined user is available.SMSC Overview An SMS center (SMSC) is responsible for handling the SMS operations of a wireless network.When an SMS message is sent from a mobile phone, it will reach an SMS center first. The SMS center then forwards the SMS message towards the destination. The main duty of an SMSC is to route SMS messages and regulate the process. If the recipient is unavailable the SMSC will store the SMS message. It will forward the SMS message when the recipient is available.

Network Architecture

SMS technical realization The SMS is realized by the use of the Mobile Application Part (MAP) of the SS#7 protocolThese MAP messages may be transported using 'traditional' TDM based signaling, or over IP using SIGTRAN and an appropriate adaptation layer.SMS on Store and forward technique.SMS Call FlowBasic SMS Call Flow :End to end SMS transaction completes in 2 parts :Message submission by originating subscriber to its SMSC (Mobile Originating Part)Message delivery by SMSC to recipient Subscriber (Mobile terminating Part)

9SMS Call Flow

MO-SM SubmitThe SM is sent from the originating Mobile Station (MS) to the serving Mobile Switching Center (MSC). The address of the SMSC where the SM should be submitted to is stored on the SIM card of the subscriber and forwarded to the MSC with the message.The MSC forwards the SM to the SMSC. The SMSC returns a positive (ACK) or negative (NACK) response indicating whether the message was successfully stored of not.

MT-SM DeliverTo delivers a SM SMSC has to find out the location (serving MSC) and the International Mobile Subscriber Identity (IMSI) of the recipient subscriber first. This information (routing information) is retrieved from the Home Location Register (HLR) of the recipient subscriber based on the recipient number (MSISDN). HLR Provides routing Information to SMSC, which includes IMSI and serving MSC of recipient number. Based on routing information SMSC delivers SM to the serving MSC and MSC forwards it to the recipient Mobile Station.