Quick help quide to GSM PDU mode structure

Transcription

1 1 (6) Quick help quide to GSM PDU mode structure AT+CMGS Send Message Sends a message from the DTE to the network (SMS-SUBMIT): AT+CMGS=<length><CR>PDU<ctrl-Z/ESC> <length> The length of the actual TPDU in octets. The RP layer SC address octets are not counted in the length. <pdu> RP SC address Address-Value field followed by a TPDU in hexadecimal format. Sending can be canceled by using an <ESC> character. <ctrl-z> must be used to indicate the ending of a message body. Message reference value <mr> is returned to the DTE on successful message delivery: +CMGS: <mr> <mr> TP-Message-reference in integer format. SMS-DELIVERs are routed directly to the DTE using this kind of result code: +CMT: [<alpha>],<length><cr><lf><pdu> <alpha> String type alphanumeric representation of <da> or <oa> corresponding to the entry found in MT phonebook, implementation of this feature is manufacturer specific. <length> The length of the actual TPDU in octets. The RP layer SC address octets are not counted in the length. <pdu> RP SC address Address-Value field followed by TPDU in hexadecimal format. SMS-SUBMIT and SMS-DELIVER are TPDUs (Transfer Protocol Data Unit) Those can be build in different way, structure is explained more detailed in GSMS specification. SUBMIT goes from phone to network and DELIVER is coming from network to phone. An example of sending and receiving a routed short message with the SMS PDU mode is presented here. SMS-SUBMIT AT+CMGF=0 set SMS PDU mode on OK AT+CNMI=1,2 forward received SMS-DELIVERs to TE OK AT+CMGS=29 length of the SMS PDU C A A0E4ACf41f4f29C9E769F4121 +CMGS: 212 message reference is shown OK +CMT:, C A0E4ACF41F4F29C9E769F412 1

2 2 (6) SMS-SUBMIT protocol structure 07 91address length: 7, type of address is international using ISDN telephone numbering plan SC address: (not mandatory) 11 SMS-SUBMIT, do not reject duplicates in SC, validity period not present, no status report request, no header in user data, reply path not set (GSM 03.40) 00 TP message reference, given by the phone 0C 91 address length: 12, type of address is international using ISDN telephone numbering plan destination address: protocol identifier: straightforward, data coding scheme: default class, 7 bit message A7 validity period A 0E 4A CF 41 F4 F2 9C 9E 76 9F length of user data 17, user data Service Center numbers is not mandatory field in PDU structure. Here is example in same message without SMSC number. AT+CMGS= C A A0E4Acf41f4f29C9E769F4121 SMS-DELIVER +CMT:, C A0E4ACF41F4F29C9E769F412 1 SMS-DELIVER protocol structure 07 91address length: 7, type international using ISDN numbering plan SC address

3 3 (6) 20 SMS-DELIVER, more messages are waiting for the MS in this SC, status report will be returned to the sender, no header in the beginning of user data, no reply path 0C 91 address length: 12, type of address is international using ISDN telephone numbering plan originating address protocol identifier straightforward, data coding scheme: class default, 7 bit data SC time stamp A 0E 4A CF 41 F4 F2 9C 9E 76 9F length of user data: 17, user data SC address GSM SC address followed by GSM TPDU in hexadecimal format. AT+CMGS=5 > c a70141 <ctrl> Z SC address (GSM 04.11), SC address length is count of octets 11 <fo> 00 TP Message Reference 0c TP-Destination-Address, destination address length is count of digits 00 TP-Protocol-Identifier 00 TP-Data-Coding-Scheme a7 TP-Validity Period 01 TP-User-Data-Length 41 TP-User-Data

4 4 (6) MESSAGE CLASSES There are 5 different classes in Short message service: Class Default No specific class is in use. Message is normally stored in the active memory of a phone Class 0 Phone will immediately display the received short message. The message is not automatically stored. Class 1 Received message will be stored to the phone memory Class 2 Received message will be stored to SIM-card memory Class 3 Received message will be routed to terminal (terminal specific message) When default class is used the user data is always coded using the 7-bit alphabet. In all other classes 8-bit or 16-bit character coding is accepted. When 8-bit character coding is used the message contain 140 characters and when 16-bit (unicode) is used the message may contain 70 characters uncompressed user data.

5 5 (6) GSM Text and PDU-mode protocol identifiers (GSM 03.38) 7-bit PDU-mode Text-mode Class 0 F0 AT+CSMP=,,, AT+CSMP=,,,16 Class 1 F1 AT+CSMP=,,, AT+CSMP=,,,17 Class 2 F2 AT+CSMP=,,, AT+CSMP=,,,18 Class 3 F3 AT+CSMP=,,, AT+CSMP=,,,19 8-bit Class 0 F4 AT+CSMP=,,, AT+CSMP=,,,20 Class 1 F5 AT+CSMP=,,, AT+CSMP=,,,21 Class 2 F6 AT+CSMP=,,, AT+CSMP=,,,22 Class 3 F7 AT+CSMP=,,, AT+CSMP=,,,23 Unicode E0 AT+CSMP=,,, AT+CSMP=,,,8 CBS-unicode 48 AT+CSMP=,,,72 CBS-8bit 44 AT+CSMP=,,,64 F4 AT+CSMP=,,,8 CBS-Class3 53 AT+CSMP=,,,224 F3 AT+CSMP=,,,8

6 6 (6) Examples 7-bit user data, sending by using default class. User data is coded to seven databits, because SMS have to be sent to air in 7 bit format. AT+CMGS= c f0a70CD4E2940A6A16A7D3E0B108 8 data bits user data, it can be set enabled by setting protocol identifier to value F5 (Class 1). AT+CMGS= c f5a70BF4F29C0E6A97E7F3F0B90C User data is same in both examples: TEST MESSAGE. SMS Routing AT command AT+CNMI can be used to route SMS to to place where is needed. e.g. by using command: AT+CNMI=1,2,2,1,0<CR>) the application can receive the incoming SMSs directly in all environments. More information can be found from GSMS specificaton. Specifications Following ETSI made GSM specifications are needed, when GSM Text- and PDU-mode is used. GSM GSM GSM GSM GSM GSM Address to ETSI web pages is: