SMS gateway

An SMS gateway or MMS gateway allows a computer (also known as a Server) to send or receive text messages in the form of Short Message Service (SMS) or Multimedia Messaging Service (MMS) transmissions between local and/or international telecommunications networks. In most cases, SMS and MMS are eventually routed to a mobile phone through a wireless carrier. SMS gateways are commonly used as a method for person-to-person to device-to-person (also known as application-to-person) communications. Many SMS gateways support content and media conversions from email, push, voice, and other formats.

Gateway types

Several mobile telephone network operators have true fixed-wire SMS services. These are based on extensions to the European Telecommunications Standards Institute (ETSI) Global System for Mobile Communications (GSM) SMS standards and allow messaging between any mix of fixed and mobile equipment. These use frequency-shift keying to transfer the message between the terminal and the Short Message Service Center (SMSC). Terminals are usually based on Digital Enhanced Cordless Telecommunications (DECT), but wired handsets and wired text-only (no voice) devices exist. Messages are received by the terminal recognising that the Caller ID is that of the SMSC and going off-hook silently to receive the message.

Implementations

GSM gateway appliance

A direct-to-mobile gateway is a device that has built-in wireless GSM connectivity. It allows SMS text messages to be sent and/or received by email, from Web pages or from other software applications by acquiring a unique identifier from the mobile phone's Subscriber Identity Module, or "SIM card". Direct-to-mobile gateways are different from SMS aggregators because they are installed on an organization's own network and connect to a local mobile network.

The connection to the mobile network is made by acquiring a SIM card number from the mobile operator and installing it in the gateway. Typically, direct-to-mobile gateway appliances are used for hundreds to thousands of text messages per month. More modern appliances now offer the capability of sending up to 100,000 messages each day. Several vendors that have historically provided GSM Gateway equipment for voice also have SMS capability. Some are more primitive than others. The more capable devices are designed with SIM management to regulate the number of SMS messages per SIM, ODBC to connect to a database, and HTTP interfaces to interact with third-party applications.

Regulation

GSM gateway equipment is covered by the Wireless Telegraphy Act in the UK and can legally be used by any business to send SMS to their own customers or prospects when using their own gateway equipment. In Canada, SMS gateway providers are regulated by the Canadian Wireless Telecommunications Association (CWTA/txt.ca). In India, it is regulated by the Telecom Regulatory Authority of India (TRAI). In Pakistan, it is regulated by the Pakistan Telecommunication Authority(PTA).

Direct-to-SMSC

A direct-to-short message service centre (SMSC) gateway is a software application, or a component within a software application, that connects directly to a mobile operator's SMSC via the Internet or direct leased line connections. The Short Message Peer-to-Peer (SMPP) protocol is typically used to convey SMS between an application and the SMSC. Direct-to-SMSC gateways are used by SMS aggregators to provide SMS services to their clients and large businesses who can justify such use. They are typically employed for high volume messaging and require a contract directly with a mobile operator.

Direct-to-SMS gateway

An SMS gateway typically sits between the end-user who needs to send/receive SMS and a mobile network's SMSC. Such gateways provide their customers with a choice of protocols, including HTTP, SMTP, Short Message Peer-to-Peer and Web Services. Providers of SMS gateway services include SMS aggregators and mobile operators. SMS gateways are also available as part of messaging services such as AOL, ICQ and others.

In order to send/receive messages with mobile subscribers, an SMS gateway connects with (i) mobile network SMSCs and/or (ii) other SMS gateways. It is, therefore, possible that an SMS gateway has a combination of connections with mobile network SMSCs and connections with other SMS gateways in order to provide its services. However, there is an increasing potential for delivery problems with SMS with increasing number of SMS gateways in the delivery chain.

Email clients

Text messages can be sent from a personal computer to mobile devices via an SMS gateway or Multimedia Messaging Service (MMS) gateway, using the most popular email client programs, such as Outlook, Thunderbird, and so on. The messages must be sent in ASCII "text-only" mode. If they are sent in HTML mode or using non-ASCII characters, they will most likely appear as nonsense on the recipient's mobile telephone.

Before the message can be sent, one must determine the domain of the mobile carrier's SMS gateway. For example, if one wants to send a message to a mobile telephone in the United States serviced by AT&T, and the telephone number is [phone], the email would be addressed as

[e-mail]

To determine the SMS gateway domain, e.g., txt.att.net, may require research - but most users know who their carrier is. The telephone number in this example for a US number is expressed as ten (10) digits, without the country code (1) and without dashes or other separator characters when composing the email address. The country code is not needed, as the 10-digit telephone number, together with the email domain, are sufficient to send the email from any location in the world.

It is useful to perform a character count before sending the message to ensure that it is within the 160-character limit. If it exceeds the limit, the SMS gateway should break the message into a set of consecutive 160-character, or shorter, messages to the mobile equipment, although breaks may occur in the middle of words.

A message sent with an email client can be simultaneously addressed to multiple mobile telephones - just as text messages sent in the usual manner between mobile telephones can be sent to multiple recipients.

SMS gateway domains for other carriers (US-based):

Mobile carrier	SMS gateway domain	MMS gateway domain
Alltel[1]	sms.alltelwireless.com	mms.alltelwireless.com
AT&T[2]	txt.att.net	mms.att.net
Boost Mobile[1]	sms.myboostmobile.com	myboostmobile.com
Consumer Cellular[3]	mailmymobile.net	mailmymobile.net
Cricket Wireless	mms.cricketwireless.net	mms.cricketwireless.net[4]
FirstNet[5]	sms.firstnet.com 1waysms.firstnet.com	sms.firstnet.com 1waysms.firstnet.com
Google Fi Wireless[6]	msg.fi.google.com	msg.fi.google.com
MetroPCS	mymetropcs.com	mymetropcs.com
Republic Wireless[7]	text.republicwireless.com
Sprint[1]	messaging.sprintpcs.com	pm.sprint.com
T-Mobile[1]	tmomail.net	tmomail.net
Ting[3]	message.ting.com
U.S. Cellular[1]	email.uscc.net	mms.uscc.net
Verizon Wireless[8]	vtext.com	vzwpix.com
Virgin Mobile[1]	vmobl.com	vmpix.com
XFinity Mobile[3]	vtext.com	mypixmessages.com

SMS gateway domains for Canadian carriers:

Mobile carrier	SMS gateway domain
Bell Canada[9]	txt.bell.ca
Bell MTS[10]	text.mts.net
Fido Solutions[11]	fido.ca
Freedom Mobile[12]	txt.freedommobile.ca (Discontinued as of December 1, 2024[19])
Koodo Mobile[13]	msg.telus.com
PC Mobile[14]	mobiletxt.ca
Rogers Communications[15]	pcs.rogers.com (Discontinued[16])
SaskTel[17]	sms.sasktel.com
Telus[18]	msg.telus.com

SMS gateway features

There are several applications for SMS gateways, including:

• Bulk/mass SMS messaging communications commonly used for customer care to marketing campaigns
• Two-way SMS messaging, designed for the exchange of messages from clients to a customer portal
• To enable the development of an SMS widget for newsletters and updates
• API allowing systems to integrate with 3rd party systems including common CRM, e-commerce, ERP, and internal platforms
• For multi-factor authentication or two-factor authentication using SMS as a channel for delivering one-time-passwords (OTPs)

See also

• Kannel (telecommunications)
• Videoconferencing
• Voice over IP

References

1. Pot, Justin (February 3, 2016). "How to send free text messages from your PC: Send texts via your email client". Digital Trends. p. 2. Archived from the original on February 5, 2016 – via Tara Calishain.
2. "Register for email-to-text message preferences". AT&T. Archived from the original on February 5, 2016.
3. "Sending emails to SMS or MMS". help.inteliquent.com. Retrieved 2023-01-10.
4. "Email to SMS gateway address | Community". 9 October 2018.
5. "FirstNet Messaging Technical Information" (PDF). FirstNet. Retrieved 1 October 2024.
6. Esparza, Jordan (February 10, 2016). "[Launch] Send and receive emails over text message". Project Fi Help Forum. Retrieved February 17, 2016. To get emails ... have them sent to your [ten‑]digit Fi number at msg.fi.google.com.... You can receive text messages as well as attachments, including images, video, and audio files up to 8MB in size.
7. "Announcing Email to SMS for Your Phone! | Republic Blog". Republic Blog. 2015-09-24. Retrieved 2018-03-19.
8. "Vtext.com FAQs | Verizon Wireless". www.verizonwireless.com. Retrieved 23 October 2015.
9. "What is text messaging and how do I use it?". Bell. Retrieved 19 July 2018.
10. "Text Messaging Instructions". BellMTS. Retrieved 19 July 2018.
11. "Email to Text Messaging". Fido. Retrieved 8 August 2018.
12. "What is email to text?". Freedom Mobile. Retrieved 8 August 2018.
13. "Email to Text". community.koodomobile.com. Retrieved 8 August 2018.
14. "How Do I ...?". PC Mobile. Retrieved 8 August 2018.
15. "Email to SMS - Set Up Email to Text on Your Phone". Rogers. Retrieved 19 July 2018.
16. "Email to SMS service discontinued". communityforums.rogers.com. 2023-07-19. Retrieved 2023-11-29.
17. "Sending an email message using text messaging". SaskTel. Retrieved 19 July 2018.
18. "Send a text message by email". Telus. Archived from the original on 10 November 2016. Retrieved 19 July 2018.