What is SMS?
Short Message Service is a telecommunications protocol that allows sending short messages of 160 characters or less to mobile phones. There are two methods for sending SMS messages.
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SMTP vs SMPP
SMPP leverages dedicated mobile gateways, common shortcodes, and has a higher level of reliability amongst the carriers. These are “paid” integrations where carriers certify and approve SMS traffic. SMTP sends short messages via an email server.s This “free” from carriers offers a lower level of support and quality of service.
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What is the difference between and “MO” and “MT” SMS Messages?
MO – mobile originated. This simply refers to a user who sends a text message from their handset.
MT – mobile terminated. This simply refers to a user who receives a text message to their handset.
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How long are SMS Messages?
160 characters is the standard length.
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How quickly can you deliver SMS messages?
The actual time to deliver SMS messages varies based on the specific carrier. However, message throughput can range from 12 messages / second to 300 messages per second. Please check with your messaging / alert partner to identify their agreements with carriers and aggregators.
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What is a common shortcode?
Special abbreviated telephone numbers which are used to send and receive SMS messages. These can be 5 or 6 digits numbers which are dedicated for specific services.
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What is an SMS aggregator?
A network connectivity provider who manages shortcodes and routes SMS messages appropriately to carriers. Aggregators assist to manage network traffic, enforce standards, and monitor the quality of service with carriers and vendors.
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How much does an SMS message cost?
This is carrier dependent, but SMS messages range from 5 cents to 15 cents per message for the end user.
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What is opt-in and opt-out?
Opt in is the process by which a user that wants to participate in an SMS program accepts the terms and conditions of the program. This can be done from the mobile phone or a website. Opt out is the process by which a user that wants to stop participating in an SMS program decides to quit receiving SMS messages. This can be done from the mobile phone or a website.
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What is GPS?
Handsets can use the Global Positioning System developed by the US government with your tax dollars to obtain a very precise geographic location. When using pure GPS, the handset performs all necessary calculations itself and computes its location based on the relative distances of several orbiting satellites (via time measurements) at a very precise resolution. Because of the need to receive transmissions from multiple satellites, the handset requires a relatively unobstructed view of the sky. Furthermore, because of the limited computational power of the device and the lack of an initial reference point, a “cold start” using GPS alone may take a minute or more to provide its first result.
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GPS Fast Facts
Precision: High - 5-50 meters / 5-55 yards - about the size of a couple basketball courts
First-hit latency: High - one to two minutes
Subsequent latency: Medium - 15-30 seconds (network-initiated), Low - 5 seconds (handset-initated)
Availability: Any location with a clear, wide line-of-sight view to the sky - generally not indoors
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What is AGPS?
The Assisted Global Positioning System works very similarly to regular GPS, but faster and more robustly. In situations where fewer satellite signals are available (requiring heavy computation), the handset can off-load much of its location processing to the more powerful network hardware. The tower also provides initial location guidance, allowing the handset to obtain a “cold start” resolution much more quickly. This initial fix advantage results in AGPS’ being the preferred method over GPS for both Sprint CDMA and Nextel iDEN, regardless of setting.
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AGPS Fast Facts
Precision: High - 5-50 meters / 5-55 yards - about the size of a couple basketball courts
Latency: Medium - 15-45 seconds
Availability: Any location with a partial line-of-sight view to the sky and data service coverage - generally not indoors
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What is AFLT?
Advanced Forward Link Trilateration is conceptually similar to GPS, in that it measures signal transmission time, but relies on network towers instead of satellites. AFLT generally requires at least three cell towers in range to perform effectively. More towers will usually result in more precise locations, making this location method more accurate in densely-populated areas.
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AFLT Fast Facts
Precision: Medium - 50-200 meters / 55-220 yards - about the size of a football field
Latency: Low - <10 seconds
Availability: Any location within range of at least three network towers
Triangulation measures the angle of a signal from a target to three or more known points - in this case cell towers. Lines are plotted at these angles, and their intersection is assumed to be the location of the target.
Trilateration instead measures the distance from a target to known points. Circles with that distance as the radius are mapped out, and their intersection is identified as the target’s location.
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What is Cell Sector?
If all else fails, LBS systems can fall back on their least granular bit of handset location information: cell sector. Each tower has its sectors’ center points, or “centroids” geocoded, and any handset within a sector is assumed to be near the associated centroid, with a wide margin of error. Since the size of a given cell sector depends highly on the density of tower coverage in an area, the precision will vary according to the population.
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Cell Sector Fast Facts
Precision: Low - in practice from 500 to 5000 meters, about the size of a large university campus
Latency: Low - <10 seconds
Availability: Any location within range of a cell tower
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