I recently recommended a Siemens Gigaset S795
DECT cordless phone to a customer who wanted to be alerted about missed calls when he was out of the office by an SMS text message to his mobile.
He didn’t want a call forward to his mobile. He just wanted to know that his business number had been called. Most importantly he wanted to know the calling party number so that he could return the call when convenient.
The Gigaset S795 includes comprehensive SMS text message support and is ideal for this application.
The only potential problem with my recommendation was that the customer wanted to connect the proposed cordless phone to his office PBX phone system.
Like most cordless phones the Gigaset S795 is designed to be connected directly to a standard analogue phone line and is not guaranteed to work when connected to an analogue phone system extension. I knew that even if the phone part of the S795 worked there could be problems with the text messaging support.
Fortunately, all that was required to enable text messages to be sent was a minor change to the default S795 settings for the SMS Gateway phone number. The customer could therefore receive a text message on his mobile phone every time a call was made to his business number.
The problem with receiving text messages is that an SMS Gateway must be able to deliver Caller ID information and the text message data to the S795.
The reason that Caller ID information is essential is that an SMS phone must be able to recognise the Caller ID of its SMS Gateway. When an SMS phone recognises that an incoming call is from an SMS Gateway it automatically goes into receive mode for an SMS text message rather than a regular phone call.
The crucial difference is that when an SMS phone receives a call from an SMS Gateway it doesn’t ring. It answers the call immediately and receives a data burst containing instructions on how to receive the SMS.
If the calling party has paid for the text message then the SMS Gateway immediately delivers the message to the SMS phone in another data burst before disconnecting the call.
If the called party is to pay for receiving the text message then the SMS Gateway immediately disconnects the call. The SMS phone would then initiate a a call to the SMS Gateway to collect the waiting SMS.
The receipt of an SMS text message call is therefore unnoticed by the receiving party until the message waiting light starts flashing on the SMS phone.
In the case of my customer with the Siemens Gigaset S795
there was no problem in delivering the correct Caller ID information to the S795. However, there was a problem in delivering the text message data bursts.
I am not 100% clear on why there was a problem. There my have been a problem with the formatting of the Caller ID information by the Panasonic phone system or maybe it couldn’t cope with the SMS data bursts.
As mentioned above the S795 and similar phones have been designed to work on public analogue phone lines and not private phone systems. I would therefore expect there to be similar problems when an SMS capable phone is connected to a phone system of whatever type. However, it is impossible to be certain without trying.
Fortunately, my customer required only the facility to send text messages from his Gigaset S795. The limitation on receiving text messages was therefore not a problem.