Messaging has become an indispensable part of the telecommunication system. Voice message was first enhanced by the fax modem which opened the possibility of written text to be transmitted using a telephone line. And now the SMS has become a widely used means of written communication.
The Short Message Service (SMS) was introduced by the GSM telecommunication system in Europe more than 10 years ago but it gained popularity much later. The Extended Message Service (EMS) and the Multimedia Message Service (MMS) are new generation messaging services and still to gain mass usage. Today SMS is not limited to the mobile phone and has been adopted by the fixed line telecommunication networks as well and users can send and receive messages over PSTN and ISDN telephone connections. EMS and MMS are already operational in certain European countries but haven?t as yet gained momentum worldwide.
a) SHORT MESSAGE SERVICE (SMS) OVER FIXED NETWORK
The Short Message Service (SMS) over a fixed network is a brand new service provided by some of the European Operators. This service is gradually gaining usage outside Europe as well. It follows the SMS service provided by cellular networks like GSM and allows a short message of limited length (normally 160 characters) to be sent or received over the fixed network. The Ecom telephones exceptionally allow message length of up to 640 characters. All the new generation of Eurotelekom?s ISDN/PSTN cordless terminals are SMS enabled. In the fixed network this service can be enabled in different ways.
There are two general types of SMS over the fixed network service:
NBS (Network Based Solution)
UBS (User Based Solution)
The UBS type has two subtypes which makes it all together 3 different possibilities for implementation.
The NBS is a type of a supplementary service offered as part of a function within the public network.
The UBS is offered as part of a function within the end-user equipment, which does not require any specific short message transfer function inside the public network.
Depending on implementation, a telephone may provide SMS in the fixed network service in one country and may not be able to do so in another country even though SMS over fixed network is available in both countries. When bringing telephones from country to country users must verify with local telecom operators whether this service will work. Having a phone that supports SMS over a fixed network will not suffice until and unless the network to which the phone is connected supports this service.
The SMS messages are delivered explicitly to and dispatched by a dedicated Short Message Service Centre (SM-SC) sometimes called SMS Gateway. The SM-CS plays the role of a store and forward centre and has its own telephone number which is normally programmed by the user. It is delivered to the SMS Gateway and then sent by the Gateway to the addressee. The receiver gets the SMS message from the Gateway and not directly from the sender. The receiving terminal must support the SMS over fixed network service. It will check the number of the calling party and if it finds a match to the SMS Gate number (pre-set) it will recognize it as an SMS and indicate this to the user. The user terminal must feature CLIP (Calling Line Identity Presentation) to understand the number (Caller ID) of the Gateway. This is usually the case for an ISDN network but not so for a PSTN network.
b) ENHANCED MESSAGE SERVICE (EMS) OVER THE FIXED NETWORK
The Enhanced Message Service (EMS) is already available over some GSM networks and in some GSM telephones. This service is considered by some as an intermediate step towards Multimedia Message Service (MMS).
The basic difference between the SMS and the EMS is that the latter provides more than text. EMS offers pictures, melodies, animations and text formatting options to ?enhance? the text message with these features.
Because it is based on SMS protocol, EMS can still get accepted by a telephone not supporting EMS in the plain text format without the enhancements of picture, formatting, and sound. This gives EMS a decided advantage over similar protocols.
c) MULTI-MEDIA MESSAGE SERVICE (MMS)
Multimedia Message Service is an upgrade over the SMS and EMS. It includes video clips, higher resolution still pictures, high sound quality etc.
Like SMS, MMS is a non-real time service. A relay platform routes multimedia messages to MMS Servers and in order to be displayed the ?messages? need to be stored into the telephone?s memory.
The MMS is not a simple extension of the SMS and as such it represents a challenge for both operators and terminal designers and manufacturers. In the case of cellular, MMS will require new network infrastructure as the speed offered today for data transmission, for example by GSM, is very low. GPRS should be the first platform for MMS, the 3rd generation networks, e.g. UMTS, should be the main contributor. Additionally MMS will require MMS compliant terminals (larger high resolution displays, possibly digital cameras, etc) with a certain penetration before it can be widely used.
Although it has been launched in some European countries there are no open talks on the timeframe or on possibilities of MMS being offered on a fixed network in Middle East and Asia. The data speeds that the normal fixed networks offer today are comparable with the speeds of the commercially available GPRS system capable GSM networks in Europe. In principle any service provided over cellular (GPRS) network can be feasible over a fixed network (especially ISDN).
The future of MMS accessibility over a fixed network will depend on the end user interest in the service making it attractive for fixed network operators to develop it as a lucrative source of revenue. In any case access over a dial-up connection will be possible.
