EMS for Mobile Networks
- journal86
- Nov 28, 2024
- 2 min read
Updated: Jul 2
This paper explores the use of electromagnetic spectrum in modern digital mobile communications networks, with a particular focus on 4G Long Term Evolution (LTE) and 5G.
Digital mobile networks have evolved rapidly since the introduction of 2G (GSM (Global System for Mobile Communications)) during the early 1990s. The 2000s witnessed the introduction of 3G (UMTS (Universal Mobile Communications System)), while the 2010s brought 4G (LTE (Long Term Evolution)), and today we have 5G. This evolution has resulted in a wide range of radio frequency bands being deployed in support of mobile communications, with spectrum neutrality enabling bands which were traditionally licenced for a particular Radio Access Technology (RAT), to be repurposed for any technology. This repurposing of spectrum between RATs is known within the mobile communication industry as ‘refarming’.
The original GSM specification identified the 900 MHz band for European harmonisation, this enabled frequency alignment between countries and supported international roaming between mobile network operators of the different countries which adopted the standard. We take international roaming for granted nowadays however this wasn’t the case in the early days of cellular. First generation analogue mobile networks only operated in their home country, a range of different national standards prevented international roaming.
This was a key driver for the development of the GSM standard during the latter part of the 1980s [1]. Another worthy consideration of early GSM networks is that the mobile station (as the mobile phone is known in GSM standards) only operated on a single radio frequency band, this wasn’t an issue when all networks were planned to operate in the 900 MHz band, however quickly became a constraint as other frequency bands were introduced to enable more network operators, and therefore greater competition, along with greater overall system capacity. The second band to be adopted by the GSM standard was 1800 MHz.
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