As we inch closer to the upcoming spectrum auctions, all limelight is focused on the 800, 900, 1800 and 2100MHz frequency bands. But one of the most efficient bands for the deployment of LTE is less talked about and still remains shrouded in ambiguity, yes we are referring to the 700MHz band. The 700MHz band is one of the most sought after band for LTE deployment around the world due to its efficiency and higher penetration inside buildings and wider coverage which reduces the number of towers required for setting up the LTE network and thus significantly cuts down upon the capital expenditure involved in making the network live.
The deployment of LTE services on the 700MHz band varies greatly from country to country across the globe with each group of countries dividing the band in a unique way to facilitate the deployment of LTE services. Here we will enlist the three main patterns of LTE deployment on the 700MHz band along with the countries following that standard.
This pattern is followed in United States of America and Canada. This pattern divides the 700MHz band into 4 sub-bands known as LTE bands 12, 13, 14 and 17. All these are paired frequency bands used for FD-LTE deployment. Band 12 has 18MHz paired frequency and is being used by T-Mobile in USA. Band 13 has 10MHz paired frequency and is being used by Verizon in USA. Band 14 has 10MHz paired frequency. Band 17 has 12MHz paired frequency and is being used by AT&T in USA.
This pattern creates LTE band 28 and is currently being followed or has been chosen for deployment of FD-LTE in India, Japan, Australia, New Zealand, South Korea, Indonesia, Malaysia and Singapore. This pattern divides the 700MHz band into 45MHz of paired frequency with the lower portion of the band used for uplink and the higher portion for downlink and 10MHz in between as a guard band. This band can either be auctioned as 15 blocks of 3MHz each or 9 blocks of 5MHz each or 3 blocks of 15MHz each for optimum utilisation of spectrum.
This pattern creates LTE band 44 and as of now is only being considered for deployment of TD-LTE by China. This pattern utilises the entire 100MHz width of the 700MHz band for TD-LTE. Band 44 can accommodate a maximum of 5 carriers with 20MHz block width. Unlike FD-LTE where uplink and downlink signals are carried on distinct frequency bands, TD-LTE involves carrying both set of signals on the same frequency band.
In India, the 700MHz band is still being used for terrestrial cable analog signals in non-metro areas. In the metro cities and type A circles the 700MHz band has been freed up through phase 1 and 2 of digitisation of cable completed last year. The deadline for completion of phase 3 of digitisation is 31st December 2015 and that of phase 4 is 31st December 2016 which will cover all semi-urban and rural areas. After all 4 phases are complete we should hope to see the 700MHz band being auctioned in early 2017. Operators like Reliance Jio, Bharti Airtel, Vodafone and Idea cellular are among the ones waiting for this band to be auctioned in India for its economic and technical value.