Colloquially known as “text messaging,” Short Message Service (SMS) uses standardized communications protocols to allow web applications, mobile devices and text-enabled landlines to send and receive typed messages.
All messages are delivered either via A2P or P2P route with a registered code or mobile number for routing and tracking purposes. Depending upon route and country, the supported sender ID (code, mobile number, etc) type will vary.
- Message Length: Standard, plaintext SMS in the U.S. have a max limit of 160 characters per message. This limit varies by handset, country and message content.
- Concatenation: Some carrier networks support concatenation, which shortens the length of an individual message and chops it into segments, but stitches the content back into a single message for the end-user’s easy reading.
- Message Content: Characters can be letters, numbers or an alphanumeric combination. Non-text based SMS (such as binary) are also supported.
- Delivery Status: Due to the nature of store-and-forward technology, it is possible to receive notification of a message’s arrival at various stages in its delivery process.
- Consumer Reach: All end-users whose mobile devices support SMS can participate in SMS messaging.
- There are more mobile phones on planet earth than any other electronic device.
- Mobile users can receive SMS messages even when they can’t get phone calls or access mobile data (like emails) because SMS are sent over the carrier’s own dedicated control channel. This makes SMS the ideal form of information relay during disasters.
Just a few common examples of SMS use cases include:
- Account balance updates
- Customer feedback surveys
- Live Q&A
- Loyalty & promotional deals
- Marketing promotions and offers
- One-time password conveyance and 2FAuthentication
- Product recommendation and selection
- Reminders, alerts and notifications
- Reservation confirmations & updates
- Service notifications
- Sweepstake and contest entry
Wireless carriers, service providers and regulators aim to protect consumers from unwanted commercial messaging referred to as SPAM. The players in the mobile ecosystem don’t want text message content to suffer the same fate as email, many of which go unread due to an overload of SPAM.
Though anti-SPAM filters are used on carrier networks around the world, the governing bodies in the U.S. and Canada promote anti-SPAM best practices and enforce anti-SPAM regulation more stringently than any other countries. Most crucially, the U.S. FCC’s Telephone Communications Protection Act (TCPA) and Canada’s Anti-Spam Legislation (CASL) require all commercial messages receive consent prior to sending messages to end-users. Due to the abundance of North American messaging stipulations, you can find many articles here on Aerialink Documentation dedicated to the topic of U.S. and Canadian carrier compliance, certification and best practices.
SMS is a “store-and-forward” service. This means that before messages arrive at the destination handset, they are first routed through an SMSC–a Short Message Service Center. Networks, carriers and aggregators who support text messaging have one or more SMSCs to serve this function. If the mobile device is powered off, has a weak signal, is out of range or otherwise unavailable when the SMSC attempts to forward the message, the SMSC will store the message and continue to retry the message send until the end user receives the message or the retry period expires.
The reception of an SMS does not interrupt the mobile user’s voice calls or data usage. While those features require the use of a dedicated radio channel, text messaging utilizes a signaling path that bypasses the radio channel and its traffic clutter.
The three primary wireless network technologies–GSM, CDMA and TDMA–all support SMS. GSM is the most widely used wireless technology in the world, with a market share of more than ninety percent. AT&T’s and T-Mobile’s infrastructures both use the GSM network, while Verizon and Sprint rely instead on CDMA.
Because these technologies are configured at the network operator level, differing configurations can cause variances in the behavior of SMS delivery. The specs and standards supported by the technologies also differ, but the delivery success of plain-text SMS remains very high.
The implementation of SMS differs depending upon the sender ID used and the route (A2P or P2P) chosen to carry the message traffic.
- API: REST over HTTP, SMPP 3.3, SMPP 3.4
- Carriers: United States, Canada, International
- A2P Route: Available via shared or dedicated short code or via alphanumeric ID outside of North America
- P2P Route: Available via U.S.-registered, local and international long codes
- DLR: Supported
- Incoming Keyword Matching: Supported
For dedicated short codes, the certification process takes eight-to-twelve weeks in the U.S., and three-to-six weeks in Canada. Shared short codes have a much quicker implementation time, requiring keyword commands unique to the program and not used by other Aerialink customers. U.S. P2P programs require Aerialink review and approval, but a long code program can be up and running in minutes.
This page was last updated 1539620611284