Qualcomm has announced that it is releasing a mmWave mini-macro design to help operators that are struggling with the economics of mmWave deployments.
Mini-macro cells are so called because they are small in size but have power outputs more often associated with macro cells. Qualcomm’s aim is to make it possible for operators to deploy mmWave outdoors with a reduced number of units, making it more economical to meet business models for uses such as Fixed Wireless Access.
The product essentially marries Qualcomm’s FSM200x small cell baseband chipset with a macro-power antenna. At 60dBM of EIRP (EIRP is a measure of RF power) Qualcomm says it gives operators a 240% extended range compared to a normal power mmWave small cell. Looked at another way, by using smaller units it can reduce the cost of an equivalent macro rollout by reducing baseband cost but also by avoiding higher site costs.
Gerardo Giaretta, VP of 5G RAN Infrastructure, Qualcomm said, “When you reduce the form factor you can facilitate the type of deployments you can have. So far light pole type deployments have been limited to lower power products; we are finding the right hybrid model”
Although the baseband chipset is a small cell design, Giaretta said that support for a high number of users is not an issue, because of the bandwidth available at 28/39 GHz that the radio supports.
“The challenges we have seen for mmWave are all related to coverage and cost. Usually in 4G there is a fine line between coverage, capacity and spectrum efficiency. Meaning that when you deploy a product like a RU with a BBU underneath, you have to find the right balance between how many users you support at any given time, throughput and coverage. And that is more or less the same between 4G and sub 6GHz 5G, although massive MIMO improved that.
“But what we are finding is that when you go to mmWave it is slightly different; mmWave deployments are mostly coverage linked. Because of the larger spectrum you can schedule a lot of users easily and the coverage is pretty small. But very often where you are limited in coverage you have a lot of capacity in the baseband processing and when you look at the network you have these expensive mmWave products which are high capacity and cost. So what we are addressing is changing the equation of what is important when you deploy a mmWave network, where the key is coverage and how many users you support at a given time is not your limiting factor.”
“We are taking the baseband chipset of our small cell, the FSM200x series, and that drives the number of users you can connect. Then we are developing brand new antenna modules that are really macro grade, creating a hybrid, driving how much power you can transmit.
“So it’s a macro grade antenna module with a cost effective baseband, a smaller baseband because we don’t need to support a high number of users.”
Giaretta added that Qualcomm especially thinks that FWA is a key use case for its Compact Macro. “We have done a lot of link analysis for both downlink and uplink, and we think this is the right product for the right TCO. It’s a way to deploy mmWave with the need for fewer base stations.”
The product will be in the field in H2, 2023, he said, although Qualcomm has not yet named any customers for the design. One vendor already in the market with mmWave small cells based on Qualcomm FSM chipset is Airspan, which it provides to Rakuten.
Aside from its 60dBM EIRP figure, Qualcomm said it was not yet releasing details such as the number of antenna elements, RF power output in Watts etc
Mini macro solutions are not a new idea in the mobile industry – many vendors have some sort of version of a higher powered compact unit, for example 2x20W solutions with a similar transmit power to the Qualcomm 60dBi. Nokia had a mini-macro product in 2016, and sold a number of mini-macros to [then] Sprint in 2017/18. Airspan itself marketed its Airharmony products as a mini macro. What Qualcomm has done is up the dBM and address the mmWave market.