Besides the completion of the main specification GSM 03.40, the detailed protocol specifications on the system interfaces also needed to be completed.
CAMEL allows the gsm SCP to block the submission (MO) or delivery (MT) of Short Messages, route messages to destinations other than that specified by the user, and perform real-time billing for the use of the service.
Finn Trosby of Telenor chaired the draft group through its first 3 years, in which the design of SMS was established.
DGMH had five to eight participants, and Finn Trosby mentions as major contributors Kevin Holley, Eija Altonen, Didier Luizard and Alan Cox.
There were also initial discussions in the subgroup WP3 network aspects chaired by Jan Audestad (Telenor).
The result was approved by the main GSM group in a June '85 document which was distributed to industry.
However, it was necessary to limit the length of the messages to 128 bytes (later improved to 160 seven-bit characters) so that the messages could fit into the existing signalling formats.
Based on his personal observations and on analysis of the typical lengths of postcard and Telex messages, Hillebrand argued that 160 characters was sufficient to express most messages succinctly.
In this way, unused resources in the system could be used to transport messages at minimal cost.However, not all text messaging systems use SMS, and some notable alternative implementations of the concept include J-Phone's Sky Mail and NTT Docomo's Short Mail, both in Japan.Email messaging from phones, as popularized by NTT Docomo's i-mode and the RIM Black Berry, also typically uses standard mail protocols such as SMTP over TCP/IP.Prior to standardized CAMEL control of the Short Message Service, IN control relied on switch vendor specific extensions to the Intelligent Network Application Part (INAP) of SS7.was sent over the Vodafone GSM network in the United Kingdom on 3 December 1992, from Neil Papworth of Sema Group (now Mavenir Systems) using a personal computer to Richard Jarvis of Vodafone using an Orbitel 901 handset.A new network element required was a specialized short message service centre, and enhancements were required to the radio capacity and network transport infrastructure to accommodate growing SMS traffic.The technical development of SMS was a multinational collaboration supporting the framework of standards bodies.SMS, as used on modern devices, originated from radio telegraphy in radio memo pagers that used standardized phone protocols.These were defined in 1985 as part of the Global System for Mobile Communications (GSM) series of standards.Over time, this issue was eliminated by switch billing instead of billing at the SMSC and by new features within SMSCs to allow blocking of foreign mobile users sending messages through it.By the end of 2000, the average number of messages reached 35 per user per month, SMS was originally designed as part of GSM, but is now available on a wide range of networks, including 3G networks.