Reliance Jio which is currently the largest holder of liberalised spectrum in the telecom sector has recently started testing carrier aggregation of band 3 (1800 MHz) spectrum with band 5 (850 MHz) spectrum in Kerala circle and may soon launch LTE-A on a pan India scale. The operator currently holds liberalised airwaves in 2300 MHz and 850 MHz pan India and in 1800 MHz in 18 out of the total 22 circles.
In the above pic, the screenshot on the left shows primary coverage of band 5 (5 MHz channel) aggregated with band 3 (5 MHz channel) while the screenshot on the right shows primary coverage of band 3 (5 MHz channel) aggregated with band 5 (5 MHz channel). The screenshot in the center shows the LTE+ sign indicating active LTE-A while on a voice call. As reported by the tipster, in areas of good 2300 MHz coverage there is regular LTE symbol displaying, while in areas where 2300 MHz is weak or absent and 1800 and 850 MHz are both present, the cell shows LTE+ symbol denoting LTE-A. In areas where only 1800 or only 850 MHz is present there is no aggregation.
Carrier aggregation in simple words is the standard of technology which helps operators in combining their spectrum holdings spread out across various bands into one big chunk of spectrum, much like combining many smaller diameter pipes into one thick pipe with larger diameter.
The aggregation can be intra band where non contiguous spectrum within the band can be made contiguous or it can be inter band where spectrum held in different bands can be combined. The DOT has already undertaken a strenuous activity of harmonising spectrum across various bands and making the spectrum held by operators contiguous thus eliminating the need for intra band aggregation.
LTE is deployed in either FDD or TDD standard using spectrum blocks of 1.4/3/5/10/20 MHz and a maximum of 5 carriers can be aggregated which means a maximum bandwidth of 100 MHz can be achieved using LTE-A and theoretical peak speeds of 300 Mbps can be achieved with this setup. Jio has aggregated two carriers of 5 MHz each in bands 3 and 5 and as reported by the tipster it is currently delivering peak speeds of around 50 Mbps. In the current scenario even high end phones only support dual carrier aggregation, later with the maturing of device ecosystem with devices supporting triple carrier aggregation, Jio may also include band 40 in the mix to further increase the bandwidth capacity.
Thanks Firoz Khan for sharing the screenshots.