AsiaSat questions C-band 5G role
May 26, 2020
By Colin Mann
A white paper from satellite operator AsiaSat argues that C-band is not the correct band to support the key performance indicators (#KPI) promised by 5G.
In the white paper – titled Choosing the Right Spectrum for 5G – Hai Hu, Senior Communications Systems Engineer, AsiaSat, notes that higher data rates, ultra-low latency and massive machine-type connections are some of the promises of 5G mobile communication that have caught tremendous media attention.
“In order to make 5G possible, mobile operators have taken up a number of different frequency bands, including C-band spectrum, which has been used by satellites for over five decades,” he notes. “In a number of countries and regions, some portions of C-band spectrum have been seized upon by mobile operators to ‘kick-start’ the 5G commercial deployment. But as we should argue, C-band is not the correct band to support the key performance indicators (KPIs) promised by 5G,” he contends.
“For decades, the use of satellite has complemented landline infrastructure to connect the world’s underserved regions, with C-band spectrum being used by GEO communication satellites to provide comprehensive coverage over a continental-wide footprint. The current C-band 5G network deployment amounts to only a transitional phase for the mobile industry, however it has significantly disrupted the existing C-band satellite services. To understand the interplay between 5G and satellite communications, we should first look at whether all the talks about using C-band 5G to unlock the benefits of 5G is as good as it seems,” he suggests.
“5G is often touted as a next-generation technology that will transform the world, which warrants taking C-band spectrum away from satellite-based applications. The real story may not be so simple,” he adds.
“First, the 5G KPIs may look attractive, but they can only be achieved with the deployment of higher frequency bands down the road. Looking at the history of mobile communication, it appears to take a whole decade or even longer to complete the handover from one generation to the next. The reallocation of C-band spectrum seems to support the launch of 5G, but it provides only an incremental improvement over existing service and will not shorten the 4G to 5G transition. For realising the KPI goals, the 5G network will eventually have to migrate to higher frequencies with much wider available spectrum. If it does not, 5G will turn out to be a wasteful investment with little benefits to the society.”
“Second, any direct comparison of spectrum use by satellite and 5G may be short-sighted and misguided because the benefits of C-band often extend beyond the borders of a domestic market. Satellite can complement landline infrastructure by bringing much-needed connectivity to the underserved regions. The current reallocation of C-band spectrum for 5G network amounts to only a transitional phase for the mobile industry, but it has disrupted the decades long of satellite communications. Over the last 30 years, the satellite infrastructure provided by C-band has proven itself to be essential for providing broadcast and emergency communication services, which cannot be measured by the amount of revenues generated from the use of the spectrum,” he argues.
“Finally, the use of a GEO satellite for 5G backhaul ignores the point-to-multipoint ability of satellite to provide geographically diverse services and will not bring a sustainable business model to satellite industry. Providing reliable communications links, wide area coverages and significantly increased capacity per beam, a modern GEO satellite can serve many different business sectors across the world, with mobile backhaul being only one of them. With today’s satellite technology, there is no doubt that a GEO satellite is capable of providing backhaul for partial or full-scale 5G data using wide or narrow beams. However, the extra satellite data traffic brought by the booming 5G business will have a short-lived impact – the demand will fade away as more landline connections become available,” he concludes.