Mobile spectrum- A brief history
Radio frequency or mobile spectrum is considered as one of the most basic mechanisms which are needed for the organization of telecommunication network. Voice communication through networking was developed in the late 1940s and went on to become the basics of mobile communications. Since 1950s, the mobile communication technology has gone through a series of iterations and advancements in order to make it more users friendly. During the early 70s mobile spectrum was playing a major role in DOD (department of defense) operations. Countries like USA, Russia and Japan had a dedicated spectrum which was used by their defense departments.
MTS or Mobile Telephone service
Bell Labs, one of the telecommunications pioneers introduced radio based mobile telecommunication network in the year 1947. It was known as MTS or mobile telecommunication service at that time and connected the users to a dedicated PSTN (Public Switched Telephone Network). VHF radio communication network played an important rule during that period in the development of mobile spectrum and mobile communication network. Initially, the PSTN system comprised of three channels but it was expended to 24 channels in order to cope with the increasing number of users. MTS operated on two major frequency bands which comprised of 152.48 to 152.84(for up linking the network) and 157.74 to 158.999 (as downlink for networks).
IMTS- Proper utilization of mobile spectrum
Through 1960s and 1970s, mobile telecommunication and mobile spectrum saw a series of advancements in terms of technology and user base. Bell labs were one of the first companies which introduced the highly sophisticated IMTS service for the users. It was also known as zero G network and was a combination of VHF and UHF radio frequencies. However, the era post 1990s is considered as the decade in which mobile revolution took place. The users were introduced to GSM and CDMA spectrums which later on became the backbone of modern telecommunication systems.