An SMS hub is a stand-alone system which allows you to send and receive large numbers of text messages via the mobile phone network, without needing to be connected to the internet or to any other computer network.
You need a laptop or desktop computer with a number of mobile phones or GSM modems attached. A GSM modem is a small device without a keypad or screen that you connect to your computer. It works like a mobile phone, but is controlled through the computer. Messages are sent and received using software installed on the computer which transmits them through the attached phone or modem to the available mobile phone network. Because SMS hubs do not need to be connected to the internet, they are very useful for NGOs working in areas where access to the internet is not possible or is unreliable.
It is quick, cheap and fairly easy to set up an SMS hub, which makes them ideal for organisations that have few resources and low budgets or for those that work in sensitive areas or in countries with repressive dictatorial regimes. One user of FrontlineSMS comments:
“FrontlineSMS has opened up the seemingly complex world of automated SMS message handling to a novice SMS user like myself. Based in Africa in a country where broadcast technology is controlled by a dictatorial government, this software has enabled me to embrace SMS messaging as a means to communicate with the public at large. Since the software does not require me to set up any special relationships with carriers or internet service providers I am able to run my project without drawing unnecessary attention to myself - a good thing in this neck of the woodsâ€
One of the advantages of SMS hubs is that since messages are sent using a local mobile phone and SIM card, users are able to reply through their phones, something which is not always possible if you use web-based messaging tools. (SIM cards are small plastic chips which your network operator sells to you and which allow you to access the mobile network). Web-based group messaging services, such as Clickatell or BulkSMS, are not appropriate for organisations working in places with unreliable telecommunications infrastructure or no internet connectivity at all. They also require a credit card. SMS hubs get around this by using the mobile phone network to send and receive their messages; so the messages are paid for through your SIM card
Systems which send messages via an attached GSM phone or modem generally cost more to run than web-based alternatives. You pay for each message that you send according to the network price plan and SIM card you're using. In addition, because messages are being sent out one at a time the process is generally slower, with an average of 8 to 10 text messages per minute. Online (or web-based) SMS aggregators, through which you can send large numbers of messages more quickly, are generally cheaper.
Some networks limit the number of times you can send the same text message, to prevent illegal spamming. Text messages cannot be more than 160 characters long, which limits the amount of information you can transmit.
Very high levels of mobile phone activity through a single phone number could attract the attention of the authorities, which could prove dangerous in countries with dictatorial regimes where people are often required to register their phone numbers. For further details of the security implications of using text messaging, see the section on security.
FrontlineSMS is a software application for desktop and laptop computers which does not an require an internet connection and which works with any Global System for Mobile (GSM) network. It is available in: Chinese, English, Finnish, French, German, Portuguese, Russian, Spanish and Swahili. The FrontlineSMS user community will also provide support to first time users.
SMS Server Tools 3 can provide a system for sending and retrieving text messages and also allow you to manage the some of the functions and configurations of your GSM phone or modem remotely, from your computer.