8/2/2019 LTE - Reuse GSM Assets When Launching LTE(2011)

1/1

#NSN-004 Titel [Alt+T]

The first wave of LTE networklaunches focused on new frequencybands such as 2.6 GHz or digitaldividend spectrum at 700 MHz or800 MHz. But more than 30

frequency bands have been definedfor LTE and TD-LTE deployments,and the 1800 MHz band has beenattracting considerable attentionfrom communications serviceproviders (CSPs).

Thats because many CSPs arealready running GSM networks at1800 MHz, which enables them toreuse existing GSM antennas andantenna lines in a new LTEdeployment. The coverage of abase station at 1800 MHz is roughlytwice as big as at 2.6 GHz. Thatmeans in practice that an LTErollout at 1800 MHz can be fullysupported by an existing 1800 MHzGSM (GSM1800) base station grid.

Global potential and momentumGSM1800 is used throughoutEurope, large parts of Asia Pacificand Africa, as well as Brazil.According to the Global mobileSuppliers Association (GSA), morethan 350 CSPs have been allocated

1800 MHz spectrum.

Many of these markets are waybehind the front-runner LTE

markets in allocating new frequencybands. Deploying LTE on sparecapacity in the 1800 MHz band orvia re-farming from GSM1800 istherefore an extremely effectiveway for CSPs to provide theircustomers with the low-latency andhigh downlink and uplink speedsmade possible by LTE.

Make more of existing assetsReusing the GSM sites requires

available capacity in the frequencyband, as well as physical space atthe base station site. Frequency re-farming can meet these needs,especially in combination with theFlexi Multiradio Base Station fromNokia Siemens Networks.The Flexi Multiradio Base Stationsupports concurrent GSM and LTEoperation, as demonstrated at theMobile World Congress in February2011. It enables CSPs to deploy anextremely compact, combinedGSM/LTE 1800 base station,without the need for any extra floorspace or air conditioning.

The Finnish experienceFinnish CSP Elisa, is a greatexample. The company has beenworking with Nokia SiemensNetworks on an LTE1800 trial in the

Helsinki area since 2010. InFinland, the 1800 MHz band istechnology-neutral, so Elisa hasregulatory approval to deploy LTEon this band, says Elisas TimoSippola. We have a total of25 MHz of spectrum in this band.This provides us with the potentialto combine good, existing urbanand suburban coverage with highlycompetitive data rates by initiallyusing depending on GSM traffic -

10 to 20 MHz of our spectrum forLTE. In the long term, we can re-farm further frequency blocks andwill then be able to deliver up to 150Mbps peak data rate from ourexisting GSM1800 antennas.

Even faster in futureAs more subscribers migrate fromGSM to HSPA+ and LTE over time,the drive to re-farm further GSMfrequency blocks to LTE willincrease. For example, evolving aninitial LTE1800 deployment of 10MHz band to a deployment of 20MHz band doubles the data ratesexperienced by users.The Nokia Siemens NetworksSingle RAN Advanced solutionallows for smooth re-farming via asoftware upgrade from GSM to LTEand even beyond to LTE-Advanced.

Copyright 2011 Nokia Siemens Networks.

Reuse GSM assetswhen launching LTE

The decision to launch LTE is often governed by the need to find themost cost-effective way to combine data rates, coverage andcapacity. LTE on the 1800 MHz band provides an added advantagein parts of the world where there are already GSM deployments inthe same spectrum.