10. How to Send SMS Messages from a Computer / PC?
In general, there are two ways to send SMS messages from a computer / PC to a mobile phone:
1.
Connect a mobile phone or GSM/GPRS modem to a computer / PC. Then use the computer / PC and AT commands to instruct the mobile phone or GSM/GPRS modem to send SMS messages.
2.
Connect the computer / PC to the SMS center (SMSC) or SMS gateway of a wireless carrier or SMS service provider. Then send SMS messages using a protocol / interface supported by the SMSC or SMS gateway.
If you do not want to develop SMS software or applications but just want to use your computer / PC to send text messages, you may want to read our Quick Guide for Non-Developers.
10.1. The 1st Way: Sending SMS Messages from a Computer Using a Mobile Phone or GSM/GPRS Modem
Preferences - Do not show ads
The SMS specification has defined a way for a computer to send SMS messages through a mobile phone or GSM/GPRS modem. A GSM/GPRS modem is a wireless modem that works with GSM/GPRS wireless networks. A wireless modem is similar to a dial-up modem. The main difference is that a wireless modem transmits data through a wireless network whereas a dial-up modem transmits data through a copper telephone line. More information about GSM/GPRS modems will be provided in the section "Introduction to GSM / GPRS Wireless Modems". Most mobile phones can be used as a wireless modem. However, some mobile phones have certain limitations comparing to GSM/GPRS modems. This will be discussed in the section "Which is Better: Mobile Phone or GSM / GPRS Modem" later.
To send SMS messages, first place a valid SIM card from a wireless carrier into a mobile phone or GSM/GPRS modem, which is then connected to a computer. There are several ways to connect a mobile phone or GSM/GPRS modem to a computer. For example, they can be connected through a serial cable, a USB cable, a Bluetooth link or an infrared link. The actual way to use depends on the capability of the mobile phone or GSM/GPRS modem. For example, if a mobile phone does not support Bluetooth, it cannot connect to the computer through a Bluetooth link.
After connecting a mobile phone or GSM/GPRS modem to a computer, you can control the mobile phone or GSM/GPRS modem by sending instructions to it. The instructions used for controlling the mobile phone or GSM/GPRS modem are called AT commands. (AT commands are also used to control dial-up modems for wired telephone system.) Dial-up modems, mobile phones and GSM/GPRS modems support a common set of standard AT commands. In addition to this common set of standard AT commands, mobile phones and GSM/GPRS modems support an extended set of AT commands. One use of the extended AT commands is to control the sending and receiving of SMS messages.
The following table lists the AT commands that are related to the writing and sending of SMS messages:
AT command
Meaning
+CMGS
Send message
+CMSS
Send message from storage
+CMGW
Write message to memory
+CMGD
Delete message
+CMGC
Send command
+CMMS
More messages to send
One way to send AT commands to a mobile phone or GSM/GPRS modem is to use a terminal program. A terminal program's function is like this: It sends the characters you typed to the mobile phone or GSM/GPRS modem. It then displays the response it receives from the mobile phone or GSM/GPRS modem on the screen. The terminal program on Microsoft Windows is called HyperTerminal. More details about the use of Microsoft HyperTerminal can be found in the "How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem" section of this SMS tutorial.
Below shows a simple example that demonstrates how to use AT commands and the HyperTerminal program of Microsoft Windows to send an SMS text message. The lines in bold type are the command lines that should be entered in HyperTerminal. The other lines are responses returned from the GSM / GPRS modem or mobile phone.
AT
OK
AT+CMGF=1
OK
AT+CMGW="+85291234567"
> A simple demo of SMS text messaging.
+CMGW: 1
OK
AT+CMSS=1
+CMSS: 20
OK
Here is a description of what is done in the above example:
*
Line 1: "AT" is sent to the GSM / GPRS modem to test the connection. The GSM / GPRS modem sends back the result code "OK" (line 2), which means the connection between the HyperTerminal program and the GSM / GPRS modem works fine.
*
Line 3: The AT command +CMGF is used to instruct the GSM / GPRS modem to operate in SMS text mode. The result code "OK" is returned (line 4), which indicates the command line "AT+CMGF=1" has been executed successfully. If the result code "ERROR" is returned, it is likely that the GSM / GPRS modem does not support the SMS text mode. To confirm, type "AT+CMGF=?" in the HyperTerminal program. If the response is "+CMGF: (0,1)" (0=PDU mode and 1=text mode), then SMS text mode is supported. If the response is "+CMGF: (0)", then SMS text mode is not supported.
*
Line 5 and 6: The AT command +CMGW is used to write an SMS text message to the message storage of the GSM / GPRS modem. "+85291234567" is the recipient mobile phone number. After typing the recipient mobile phone number, you should press the Enter button of the keyboard. The GSM / GPRS modem will then return a prompt "> " and you can start typing the SMS text message "A simple demo of SMS text messaging.". When finished, press Ctrl+z of the keyboard.
*
Line 7: "+CMGW: 1" tells us that the index assigned to the SMS text message is 1. It indicates the location of the SMS text message in the message storage.
*
Line 9: The result code "OK" indicates the execution of the AT command +CMGW is successful.
*
Line 10: The AT command +CMSS is used to send the SMS text message from the message storage of the GSM / GPRS modem. "1" is the index of the SMS text message obtained from line 7.
*
Line 11: "+CMSS: 20" tells us that the reference number assigned to the SMS text message is 20.
*
Line 13: The result code "OK" indicates the execution of the AT command +CMSS is successful.
To send SMS messages from an application, you have to write the source code for connecting to and sending AT commands to the mobile phone or GSM/GPRS modem, just like what a terminal program does. You can write the source code in C, C++, Java, Visual Basic, Delphi or other programming languages you like. However, writing your own code has a few disadvantages:
*
You have to learn how to use AT commands.
*
You have to learn how to compose the bits and bytes of an SMS message. For example, to specify the character encoding (e.g. 7-bit encoding and 16-bit Unicode encoding) of an SMS message, you need to know which bits in the message header should be modified and what value should be assigned.
*
Sending SMS messages with a mobile phone or GSM/GPRS modem has a drawback -- the SMS transmission speed is low. As your SMS messaging application becomes more popular, it has to handle a larger amount of SMS traffic and finally the mobile phone or GSM/GPRS modem will not be able to take the load. To obtain a high SMS transmission speed, a direct connection to an SMSC or SMS gateway of a wireless carrier or SMS service provider is needed. However, AT commands are not used for communicating with an SMS center or SMS gateway. This means your have to make a big change to your SMS messaging application in order to move from a wireless-modem-based solution to a SMSC-based solution.
In most cases, instead of writing your own code for interacting with the mobile phone or GSM/GPRS modem via AT commands, a better solution is to use a high-level SMS messaging API (Application programming interface) / SDK (Software development kit) / library. The API / SDK / library encapsulates the low-level details. So, an SMS application developer does not need to know AT commands and the composition of SMS messages in the bit-level. Some SMS messaging APIs / SDKs / libraries support SMSC protocols in addition to AT commands. To move from a wireless-modem-based SMS solution to a SMSC-based SMS solution, usually you just need to modify a configuration file / property file or make a few changes to your SMS messaging application's source code.
Preferences - Do not show ads
The links to some open source and free SMS messaging libraries can be found in the article "Free Libraries/Tools for Sending/Receiving SMS with a Computer".
Another way to hide the low-level AT command layer is to place an SMS gateway between the SMS messaging application and the mobile phone or GSM/GPRS modem. (This has been described in the section "What is an SMS Gateway?" earlier.) Simple protocols such as HTTP / HTTPS can then be used for sending SMS messages in the application. If an SMSC protocol (e.g. SMPP, CIMD, etc) is used for communicating with the SMS gateway instead of HTTP / HTTPS, an SMS messaging API / SDK / library can be very helpful to you since it encapsulates the SMSC protocol's details.
Usually a list of supported / unsupported mobile phones or wireless modems is provided on the web site of an SMS messaging API / SDK / library or an SMS gateway software package. Remember to check the list if you are going to use an SMS messaging API / SDK / library or an SMS gateway software package.
10.1.1. Major Drawback of Sending SMS Messages through a Mobile Phone or GSM/GPRS Modem -- Low SMS Sending Rate
Using a mobile phone or GSM/GPRS modem to send SMS messages has a major drawback, that is the SMS sending rate is too low. Only 6-10 SMS messages can be sent per minute (when the "SMS over GSM" mode is used). The performance is not affected by the connection between the computer and the mobile phone or GSM/GPRS modem (i.e. the SMS sending rate is about the same no matter the mobile phone or GSM/GPRS modem is connected to the computer through a serial cable, USB cable, Bluetooth link or infrared link) and does not depend on whether a mobile phone or GSM/GPRS modem is used (i.e. the SMS sending rate is about the same no matter a mobile phone or a GSM/GPRS modem is used). The determining factor for the SMS sending rate is the wireless network.
Page 10 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Sunday, February 3, 2008
9. What is an SMS Gateway?
9. What is an SMS Gateway?
Preferences - Do not show ads
One problem of SMS messaging is that SMSCs developed by different companies use their own communication protocol and most of these protocols are proprietary. For example, Nokia has an SMSC protocol called CIMD whereas another SMSC vendor, CMG, has an SMSC protocol called EMI. We cannot connect two SMSCs if they do not support a common SMSC protocol. To deal with this problem, an SMS gateway is placed between two SMSCs. This is illustrated in the following figure. The SMS gateway acts as a relay between the two SMSCs. It translates one SMSC protocol to another one. This way can be used by two different wireless carriers to interconnect their SMSCs for purposes such as enabling the exchange of inter-operator SMS messages.
Figure 1. An SMS gateway acts as a relay between two SMS centers.
Besides wireless carriers, content providers and SMS application developers may also find an SMS gateway useful. Let's consider the following situation. Suppose you are the developer of an SMS text messaging application. To send and receive SMS text messages on your server, one way is to connect to the SMSCs of the wireless carriers. Different wireless carriers may use SMSCs from different vendors, which means your SMS text messaging application may need to support multiple SMSC-specific protocols. (This is illustrated in the following figure). As a result, the SMS text messaging application's complexity and development time increases.
Figure 2. An SMS text messaging application connects to SMSCs without an SMS gateway.
To deal with the above problem, an SMS gateway can be set up to handle the connections to the SMSCs. Now the SMS text messaging application only needs to know how to connect to the SMS gateway. To support more SMSCs, you just need to modify the settings of the SMS gateway. No change to the source code of the SMS text messaging application is required. The use of an SMS gateway can greatly shorten the SMS text messaging application's development time.
To connect to an SMS gateway, you can use an SMSC protocol such as SMPP and CIMD. Some SMS gateways support an HTTP / HTTPS interface. HTTP / HTTPS is easier to use than SMSC protocols. The drawback is that there may be fewer SMS features to use. For example, an SMS gateway may not support the sending of picture messages through the HTTP / HTTPS interface.
Figure 3. An SMS text messaging application connects to SMSCs through an SMS gateway.
Preferences - Do not show ads
Besides using a direct connection to the SMSC of a wireless carrier, another way to send and receive SMS text messages on a computer is to use a mobile phone or GSM/GPRS modem. To do this, your SMS text messaging application has to know how to communicate with the mobile phone or GSM/GPRS modem using AT commands.
Some SMS gateways are capable of handling the connections to mobile phones and GSM/GPRS modems. To send and receive SMS text messages with a mobile phone or GSM/GPRS modem, the SMS text messaging application only needs to know how to talk to the SMS gateway and does not need to know anything about AT commands. More details about GSM/GPRS modems and AT commands will be provided in later sections of this SMS tutorial.
Figure 4. An SMS text messaging application connects to a pool of mobile phones or GSM/GPRS modems through an SMS gateway.
9.1. Open Source and Free SMS Gateway Software
As you can see in the above sections, an SMS gateway has a lot of responsibilities in an SMS messaging system. So, SMS gateway software can be very complex and complex software is usually expensive. Fortunately, there are open source SMS gateway software packages that can be downloaded free of charge over the web. One high-quality free SMS gateway software package is Kannel, which is written in the C programming language. Kannel 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. More information about Kannel can be found on its web site http://www.kannel.org/.
Page 9 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Preferences - Do not show ads
One problem of SMS messaging is that SMSCs developed by different companies use their own communication protocol and most of these protocols are proprietary. For example, Nokia has an SMSC protocol called CIMD whereas another SMSC vendor, CMG, has an SMSC protocol called EMI. We cannot connect two SMSCs if they do not support a common SMSC protocol. To deal with this problem, an SMS gateway is placed between two SMSCs. This is illustrated in the following figure. The SMS gateway acts as a relay between the two SMSCs. It translates one SMSC protocol to another one. This way can be used by two different wireless carriers to interconnect their SMSCs for purposes such as enabling the exchange of inter-operator SMS messages.
Figure 1. An SMS gateway acts as a relay between two SMS centers.
Besides wireless carriers, content providers and SMS application developers may also find an SMS gateway useful. Let's consider the following situation. Suppose you are the developer of an SMS text messaging application. To send and receive SMS text messages on your server, one way is to connect to the SMSCs of the wireless carriers. Different wireless carriers may use SMSCs from different vendors, which means your SMS text messaging application may need to support multiple SMSC-specific protocols. (This is illustrated in the following figure). As a result, the SMS text messaging application's complexity and development time increases.
Figure 2. An SMS text messaging application connects to SMSCs without an SMS gateway.
To deal with the above problem, an SMS gateway can be set up to handle the connections to the SMSCs. Now the SMS text messaging application only needs to know how to connect to the SMS gateway. To support more SMSCs, you just need to modify the settings of the SMS gateway. No change to the source code of the SMS text messaging application is required. The use of an SMS gateway can greatly shorten the SMS text messaging application's development time.
To connect to an SMS gateway, you can use an SMSC protocol such as SMPP and CIMD. Some SMS gateways support an HTTP / HTTPS interface. HTTP / HTTPS is easier to use than SMSC protocols. The drawback is that there may be fewer SMS features to use. For example, an SMS gateway may not support the sending of picture messages through the HTTP / HTTPS interface.
Figure 3. An SMS text messaging application connects to SMSCs through an SMS gateway.
Preferences - Do not show ads
Besides using a direct connection to the SMSC of a wireless carrier, another way to send and receive SMS text messages on a computer is to use a mobile phone or GSM/GPRS modem. To do this, your SMS text messaging application has to know how to communicate with the mobile phone or GSM/GPRS modem using AT commands.
Some SMS gateways are capable of handling the connections to mobile phones and GSM/GPRS modems. To send and receive SMS text messages with a mobile phone or GSM/GPRS modem, the SMS text messaging application only needs to know how to talk to the SMS gateway and does not need to know anything about AT commands. More details about GSM/GPRS modems and AT commands will be provided in later sections of this SMS tutorial.
Figure 4. An SMS text messaging application connects to a pool of mobile phones or GSM/GPRS modems through an SMS gateway.
9.1. Open Source and Free SMS Gateway Software
As you can see in the above sections, an SMS gateway has a lot of responsibilities in an SMS messaging system. So, SMS gateway software can be very complex and complex software is usually expensive. Fortunately, there are open source SMS gateway software packages that can be downloaded free of charge over the web. One high-quality free SMS gateway software package is Kannel, which is written in the C programming language. Kannel 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. More information about Kannel can be found on its web site http://www.kannel.org/.
Page 9 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
8. International SMS Messages
8. International SMS Messages
Preferences - Do not show ads
Inter-operator SMS messages can be further divided into two categories -- local inter-operator SMS messages and international inter-operator SMS messages (international SMS messages). A local inter-operator SMS message is an SMS message that is sent from one wireless network operator to another wireless network operator in the same country, while an international SMS message is an SMS message that is sent from a wireless network operator in one country to a wireless network operator in another country.
Usually the cost for sending an international SMS message from a mobile phone is higher than that for sending a local inter-operator SMS message. Hence, the cost for sending an intra-operator SMS message <= the cost for sending a local inter-operator SMS message <= the cost for sending an international SMS message.
The interoperability of SMS messaging between two wireless networks locally and even internationally is undoubtedly a main factor that contributes to the success of SMS worldwide.
Page 8 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Preferences - Do not show ads
Inter-operator SMS messages can be further divided into two categories -- local inter-operator SMS messages and international inter-operator SMS messages (international SMS messages). A local inter-operator SMS message is an SMS message that is sent from one wireless network operator to another wireless network operator in the same country, while an international SMS message is an SMS message that is sent from a wireless network operator in one country to a wireless network operator in another country.
Usually the cost for sending an international SMS message from a mobile phone is higher than that for sending a local inter-operator SMS message. Hence, the cost for sending an intra-operator SMS message <= the cost for sending a local inter-operator SMS message <= the cost for sending an international SMS message.
The interoperability of SMS messaging between two wireless networks locally and even internationally is undoubtedly a main factor that contributes to the success of SMS worldwide.
Page 8 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
7. Inter-operator SMS Messages
7. Inter-operator SMS Messages
Preferences - Do not show ads
Suppose you and your friend are using the mobile phone service of wireless network operator A and wireless network operator B respectively. The transmission of an SMS message from you to your friend involves two wireless networks. This SMS message is called an inter-operator SMS message.
Typically, the cost for sending an inter-operator SMS message from a mobile phone is higher than that for sending an intra-operator SMS message.
7.1. Transmission Process of Inter-operator SMS Messages
The transmission of an inter-operator SMS message involves one or more SMS centers. Generally, there are two different ways for the transmission of inter-operator SMS messages. In the first way, signaling interconnections are set up between two wireless networks. When the originator SMS center receives an inter-operator SMS message, it gets the routing information from the recipient wireless network and delivers the SMS message to the recipient mobile phone directly. The following figure illustrates the transmission process:
The first way can be used if the two wireless networks involved in the transmission of the inter-operator SMS message are based on similar technologies. However, if this is not true, the second way has to be used. For example, when an SMS message is sent from a GSM network to a CDMA network. In the second way, the originator SMS center and the recipient SMS center are interconnected through an SMS gateway or with a communication protocol that is supported by both SMS centers. The SMS message first reaches the originator SMS center, which will then forward the SMS message towards the recipient SMS center. The recipient SMS center will be responsible for sending the SMS message to the recipient mobile phone and storing the SMS message if the recipient mobile phone is offline. The following figure illustrates the transmission process:
Page 7 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Preferences - Do not show ads
Suppose you and your friend are using the mobile phone service of wireless network operator A and wireless network operator B respectively. The transmission of an SMS message from you to your friend involves two wireless networks. This SMS message is called an inter-operator SMS message.
Typically, the cost for sending an inter-operator SMS message from a mobile phone is higher than that for sending an intra-operator SMS message.
7.1. Transmission Process of Inter-operator SMS Messages
The transmission of an inter-operator SMS message involves one or more SMS centers. Generally, there are two different ways for the transmission of inter-operator SMS messages. In the first way, signaling interconnections are set up between two wireless networks. When the originator SMS center receives an inter-operator SMS message, it gets the routing information from the recipient wireless network and delivers the SMS message to the recipient mobile phone directly. The following figure illustrates the transmission process:
The first way can be used if the two wireless networks involved in the transmission of the inter-operator SMS message are based on similar technologies. However, if this is not true, the second way has to be used. For example, when an SMS message is sent from a GSM network to a CDMA network. In the second way, the originator SMS center and the recipient SMS center are interconnected through an SMS gateway or with a communication protocol that is supported by both SMS centers. The SMS message first reaches the originator SMS center, which will then forward the SMS message towards the recipient SMS center. The recipient SMS center will be responsible for sending the SMS message to the recipient mobile phone and storing the SMS message if the recipient mobile phone is offline. The following figure illustrates the transmission process:
Page 7 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
6. Intra-operator SMS Messages
6. Intra-operator SMS Messages
Preferences - Do not show ads
If both you and your friend are using the mobile phone service of the same wireless network operator, the transmission of an SMS message from you to your friend will involve only one wireless network operator. This SMS message is called an intra-operator SMS message.
Typically, the cost for sending an intra-operator SMS message from a mobile phone is lower than that for sending other kinds of SMS messages such as inter-operator SMS messages. Some wireless network operators allow their subscribers to send unlimited intra-operator SMS messages free of charge.
6.1. Transmission Process of Intra-operator SMS Messages
The transmission of an intra-operator SMS message involves only one SMS center. After leaving the sender, the intra-operator SMS message reaches the SMS center. The SMS center then delivers the SMS message to the recipient mobile phone. If the recipient mobile phone is offline, the SMS center stores the SMS message. It will deliver the SMS message when the recipient mobile phone is online. If the SMS message's validity period expires and the recipient mobile phone is still offline, the SMS center will remove the SMS message.
When the SMS center receives the message delivery report from the recipient mobile phone or removes the SMS message (for example, when the validity period expires), it sends a status report to the sender if the sender requested one earlier.
The following figure illustrates the transmission process of an intra-operator SMS message:
Page 6 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Preferences - Do not show ads
If both you and your friend are using the mobile phone service of the same wireless network operator, the transmission of an SMS message from you to your friend will involve only one wireless network operator. This SMS message is called an intra-operator SMS message.
Typically, the cost for sending an intra-operator SMS message from a mobile phone is lower than that for sending other kinds of SMS messages such as inter-operator SMS messages. Some wireless network operators allow their subscribers to send unlimited intra-operator SMS messages free of charge.
6.1. Transmission Process of Intra-operator SMS Messages
The transmission of an intra-operator SMS message involves only one SMS center. After leaving the sender, the intra-operator SMS message reaches the SMS center. The SMS center then delivers the SMS message to the recipient mobile phone. If the recipient mobile phone is offline, the SMS center stores the SMS message. It will deliver the SMS message when the recipient mobile phone is online. If the SMS message's validity period expires and the recipient mobile phone is still offline, the SMS center will remove the SMS message.
When the SMS center receives the message delivery report from the recipient mobile phone or removes the SMS message (for example, when the validity period expires), it sends a status report to the sender if the sender requested one earlier.
The following figure illustrates the transmission process of an intra-operator SMS message:
Page 6 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
5. Basic Concepts of SMS Technology
5. Basic Concepts of SMS Technology
In the following sections, we will introduce to you some basic concepts of the SMS technology.
5.1. Validity Period of an SMS Message
Preferences - Do not show ads
An SMS message is stored temporarily in the SMS center if the recipient mobile phone is offline. It is possible to specify the period after which the SMS message will be deleted from the SMS center so that the SMS message will not be forwarded to the recipient mobile phone when it becomes online. This period is called the validity period.
Here is an example that illustrates how validity period can be used. Suppose you find a very interesting program that is showing on TV now. You think your friend may want to watch it. So, you send a text message to tell your friend about the TV program. Let's say the TV program lasts for an hour. Your SMS text message will not be useful to your friend if his mobile phone is not available before the program finishes. In this situation, you may want to send a text message with a validity period of one hour to your friend. The wireless carrier will not deliver the SMS text message to your friend if his mobile phone is not available before the validity period ends.
A mobile phone should have a menu option that can be used to set the validity period. After setting it, the mobile phone will include the validity period in the outbound SMS messages automatically.
5.2. Message Status Reports
Sometimes you may want to know whether an SMS message has reached the recipient mobile phone successfully. To get this information, you need to set a flag in the SMS message to notify the SMS center that you want a status report about the delivery of this SMS message. The status report is sent to you in the form of an SMS message.
A mobile phone should have a menu option that can be used to set whether the status report feature is on or off. After setting it, the mobile phone will set the corresponding flag in the outbound SMS messages for you automatically. The status report feature is turned off by default on most mobile phones and GSM / GPRS modems.
5.3. Message Submission Reports
After leaving the mobile phone, an SMS message goes to the SMS center. When it reaches the SMS center, the SMS center will send back a message submission report to the mobile phone to inform whether there are any errors or failures (e.g. incorrect SMS message format, busy SMS center, etc). If there is no error or failure, the SMS center sends back a positive submission report to the mobile phone. Otherwise it sends back a negative submission report to the mobile phone. The mobile phone may then notify the user that the message submission was failed and what caused the failure.
If the mobile phone does not receive the message submission report after a period of time, it concludes that the message submission report has been lost. The mobile phone may then re-send the SMS message to the SMS center. A flag will be set in the new SMS message to inform the SMS center that this SMS message has been sent before. If the previous message submission was successful, the SMS center will ignore the new SMS message but send back a message submission report to the mobile phone. This mechanism prevents the sending of the same SMS message to the recipient multiple times.
Sometimes the message submission report mechanism is not used and the acknowledgement of message submission is done in a lower layer.
5.4. Message Delivery Reports
After receiving an SMS message, the recipient mobile phone will send back a message delivery report to the SMS center to inform whether there are any errors or failures (example causes: unsupported SMS message format, not enough storage space, etc). This process is transparent to the mobile user. If there is no error or failure, the recipient mobile phone sends back a positive delivery report to the SMS center. Otherwise it sends back a negative delivery report to the SMS center.
If the sender requested a status report earlier, the SMS center sends a status report to the sender when it receives the message delivery report from the recipient.
If the SMS center does not receive the message delivery report after a period of time, it concludes that the message delivery report has been lost. The SMS center then re-sends the SMS message to the recipient.
Sometimes the message delivery report mechanism is not used and the acknowledgement of message delivery is done in a lower layer.
Page 5 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
In the following sections, we will introduce to you some basic concepts of the SMS technology.
5.1. Validity Period of an SMS Message
Preferences - Do not show ads
An SMS message is stored temporarily in the SMS center if the recipient mobile phone is offline. It is possible to specify the period after which the SMS message will be deleted from the SMS center so that the SMS message will not be forwarded to the recipient mobile phone when it becomes online. This period is called the validity period.
Here is an example that illustrates how validity period can be used. Suppose you find a very interesting program that is showing on TV now. You think your friend may want to watch it. So, you send a text message to tell your friend about the TV program. Let's say the TV program lasts for an hour. Your SMS text message will not be useful to your friend if his mobile phone is not available before the program finishes. In this situation, you may want to send a text message with a validity period of one hour to your friend. The wireless carrier will not deliver the SMS text message to your friend if his mobile phone is not available before the validity period ends.
A mobile phone should have a menu option that can be used to set the validity period. After setting it, the mobile phone will include the validity period in the outbound SMS messages automatically.
5.2. Message Status Reports
Sometimes you may want to know whether an SMS message has reached the recipient mobile phone successfully. To get this information, you need to set a flag in the SMS message to notify the SMS center that you want a status report about the delivery of this SMS message. The status report is sent to you in the form of an SMS message.
A mobile phone should have a menu option that can be used to set whether the status report feature is on or off. After setting it, the mobile phone will set the corresponding flag in the outbound SMS messages for you automatically. The status report feature is turned off by default on most mobile phones and GSM / GPRS modems.
5.3. Message Submission Reports
After leaving the mobile phone, an SMS message goes to the SMS center. When it reaches the SMS center, the SMS center will send back a message submission report to the mobile phone to inform whether there are any errors or failures (e.g. incorrect SMS message format, busy SMS center, etc). If there is no error or failure, the SMS center sends back a positive submission report to the mobile phone. Otherwise it sends back a negative submission report to the mobile phone. The mobile phone may then notify the user that the message submission was failed and what caused the failure.
If the mobile phone does not receive the message submission report after a period of time, it concludes that the message submission report has been lost. The mobile phone may then re-send the SMS message to the SMS center. A flag will be set in the new SMS message to inform the SMS center that this SMS message has been sent before. If the previous message submission was successful, the SMS center will ignore the new SMS message but send back a message submission report to the mobile phone. This mechanism prevents the sending of the same SMS message to the recipient multiple times.
Sometimes the message submission report mechanism is not used and the acknowledgement of message submission is done in a lower layer.
5.4. Message Delivery Reports
After receiving an SMS message, the recipient mobile phone will send back a message delivery report to the SMS center to inform whether there are any errors or failures (example causes: unsupported SMS message format, not enough storage space, etc). This process is transparent to the mobile user. If there is no error or failure, the recipient mobile phone sends back a positive delivery report to the SMS center. Otherwise it sends back a negative delivery report to the SMS center.
If the sender requested a status report earlier, the SMS center sends a status report to the sender when it receives the message delivery report from the recipient.
If the SMS center does not receive the message delivery report after a period of time, it concludes that the message delivery report has been lost. The SMS center then re-sends the SMS message to the recipient.
Sometimes the message delivery report mechanism is not used and the acknowledgement of message delivery is done in a lower layer.
Page 5 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
4. What is an SMS Center / SMSC?
4. What is an SMS Center / SMSC?
Preferences - Do not show ads
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. An SMS message may need to pass through more than one network entity (e.g. SMSC and SMS gateway) before reaching the destination. The main duty of an SMSC is to route SMS messages and regulate the process. If the recipient is unavailable (for example, when the mobile phone is switched off), the SMSC will store the SMS message. It will forward the SMS message when the recipient is available.
Very often an SMSC is dedicated to handle the SMS traffic of one wireless network. A network operator usually manages its own SMSC(s) and locates them inside its wireless network system. However, it is possible for a network operator to use a third-party SMSC that is located outside the wireless network system.
You must know the address of the wireless network operator's SMSC in order to use SMS messaging with your mobile phone. Typically an SMSC address is an ordinary phone number in the international format. A mobile phone should have a menu option that can be used to configure the SMSC address. Normally, the SMSC address is pre-set in the SIM card by the wireless network operator, which means you do not need to make any changes to it.
Page 4 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Preferences - Do not show ads
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. An SMS message may need to pass through more than one network entity (e.g. SMSC and SMS gateway) before reaching the destination. The main duty of an SMSC is to route SMS messages and regulate the process. If the recipient is unavailable (for example, when the mobile phone is switched off), the SMSC will store the SMS message. It will forward the SMS message when the recipient is available.
Very often an SMSC is dedicated to handle the SMS traffic of one wireless network. A network operator usually manages its own SMSC(s) and locates them inside its wireless network system. However, it is possible for a network operator to use a third-party SMSC that is located outside the wireless network system.
You must know the address of the wireless network operator's SMSC in order to use SMS messaging with your mobile phone. Typically an SMSC address is an ordinary phone number in the international format. A mobile phone should have a menu option that can be used to configure the SMSC address. Normally, the SMSC address is pre-set in the SIM card by the wireless network operator, which means you do not need to make any changes to it.
Page 4 of 65 Previous Page | Next Page
Table of Contents
Contents at a Glance
* 1. Introduction to SMS Messaging
* 2. What Makes SMS Messaging So Successful Worldwide?
* 3. Example Applications of SMS Messaging
* 4. What is an SMS Center / SMSC?
* 5. Basic Concepts of SMS Technology
* 6. Intra-operator SMS Messages
* 7. Inter-operator SMS Messages
* 8. International SMS Messages
* 9. What is an SMS Gateway?
* 10. How to Send SMS Messages from a Computer / PC?
* 11. How to Receive SMS Messages Using a Computer / PC?
* 12. Introduction to GSM / GPRS Wireless Modems
* 13. How to Use Microsoft HyperTerminal to Send AT Commands to a Mobile Phone or GSM/GPRS Modem?
* 14. Introduction to AT Commands
* 15. General Syntax of Extended AT Commands
* 16. Result Codes of AT Commands
* 17. AT Command Operations: Test, Set, Read and Execution
* 18. Testing the Communication between the PC and GSM/GPRS Modem or Mobile Phone
* 19. Checking if the GSM/GPRS Modem or Mobile Phone Supports the Use of AT Commands to Send, Receive and Read SMS Messages
* 20. Operating Mode: SMS Text Mode and SMS PDU Mode
* 21. Setting or Reading the Service Center Address / SMSC Address (AT+CSCA)
* 22. Preferred Message Storage (AT+CPMS)
* 23. Writing SMS Messages to Memory / Message Storage (AT+CMGW)
* 24. Deleting SMS Messages from Message Storage (AT+CMGD)
* 25. Sending SMS Messages from a Computer / PC Using AT Commands (AT+CMGS, AT+CMSS)
* 26. Reading SMS Messages from a Message Storage Area Using AT Commands (AT+CMGR, AT+CMGL)
Subscribe to:
Posts (Atom)