The Short Message Service Centre SMSC MAST LOCAL

The Short Message Service Centre SMSC MAST LOCAL MOBILE NET ME ME

The Short Message Service (SMS) The SMS service uses part of the bandwidth capacity of the existing 2 G voice network. It was originally intended for use by the mobile phone companies to contact their operatives in the field undertaking maintainance work The SMSC relays SMS messages from a Mobile Equipment (ME) to another ME The SMS is sent to the nearest call mast, forwarded to the SMSC. The SMSC stores the SMS and then attempts to deliver it to the destination ME. After a preset period of time, known as the Validity Period, the message is deleted from the SMSC if it cannot be delivered. The SMS can also be forward on to a computer or logical ME is the mobile network's LAN.

INTRODUCTION TO DATA OVER GSM ANALOGUE – e. g V 22 etc SHORT MESSAGE SERVICE – SMS GPRS BASIC SMS COMMANDS AT+CMGS=”+447967123456” > ENTER TEXT CONTROL Z AT+CMGR=NN AT+CMGD=NN AT+CMGW=”+44796123456” > ENTER TEXT CONTROL Z AT+CMSS = NN

HOW TO FORMAT AN SMSC IS A LOGICAL ME NUMBER e. g. 07976 123456 1) Always use International dialling code 44 7967 123456 2) Prefix by 19 to identify this as an international dialling code 19 44 7967 123456 3) Ensure there always a pair of digits, if not back-fill with an F e. g. if we started with 07967 12345 we get 19 44 7967 12345 F 4) Avoid national dialling codes as you never know where your code will be installed national dialling codes are prefixed by 18 5) Transmit as packed BCD, which requires the BCD nibbles to be swapped around to ensure the first digit sent is the first number in the string 91 44 97 76 21 43 65 6) Prefix this all with the byte count to tell the ME how long the SMSC number is FINAL STRING 07 91 44 97 76 21 43 65 OR JUST SEND 00 FOR THE LENGTH WHEN TRANSMITTING THE ME WILL USE THE DEEFAULT PRE-SET SMSC NUMBER

SMS SUBMIT SMSC 00

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 User Header Courtesy of Dream Fabrics If set it means that the User Data has a command header prefix which contains more instructions as to how to use the data field – e. g. Multi-part messaging

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Status Report Courtesy of Dream Fabrics Request that the SMSC advise the ME of the status of the SMS forwarding e. g. proof of delivery

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Validity Period Courtesy of Dream Fabrics How to intepret the VP field, relative, enhanced, absolute or not-used

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reject Duplicate SMS Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reply path exists All commercial SMSC's ignore this Courtesy of Dream Fabrics Message Type Indicator 01 = SMS Submit

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Destination Address Length in digits excluding International dialling byte 0 C International Dialling 19 Then the Number itself 44 7967 123456 0 C 91 44 97 76 21 43 65 Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Destination Address 0 C 91 44 97 76 21 43 65 Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Destination Address 0 C 91 44 97 76 21 43 65 PID or Protocol Identifier e. g. SMS, Telefax, Telex, Voice, EMRES, Paging, Teletex, Universal Computer Interface, X 400, email and a few more But we only use SMS which is 00 Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Destination Address 0 C 91 44 97 76 21 43 65 PID 00 DCS Data Coding Scheme Courtesy of Dream Fabrics

SMS SUBMIT SMSC 00 SUM_SUBMIT 11 Reference Number 00 lets the ME decide Destination Address 0 C 91 44 97 76 21 43 65 PID 00 DCS 00 Validity Period AA = 4 days User data prefixed by a data length – NOTE 7 -bit data is compressed into 8 byte memory Courtesy of Dream Fabrics

SMS DELIVER SMSC 0791449776214365 SMS_DELIVER 04 Sender Address 0 C 91 44 97 76 21 43 65 PID 00 DCS 00 Time Stamp – Year, Month, Day, Hours, Minutes, Seconds, Time Zone Reverse BCD User data prefixed by a data length – NOTE 7 -bit data is compressed into 8 byte memory Courtesy of Dream Fabrics