Hong Kong operator SmarTone said it aims to launch 5G services next year, but still has several challenges to overcome between now and then – namely, expensive spectrum and heavy rain.
On Tuesday, SmarTone and Ericsson staged a live 5G trial for local media using the 3.5-GHz and 28-GHz bands. SmarTone intends to use the 3.5-GHz band for macro 5G coverage and the 28-GHz band for select high-density hot spots.
SmarTone and Ericsson have been testing 5G RAN technology since 2017, to include massive MIMO. SmarTone CTO Stephen Chau said that in trials so far, the 3.5 GHz band achieved downlink speeds of 1.5 Gbps and latency below 7ms, while the 28-GHz band delivered speeds of over 4 Gbps and latency just under 3ms.
Chau also said that they also found that massive MIMO enables sites using the 3.5-GHz band to provide 5G coverage similar to its 4G sites using the 2.6 GHz band.
The 28 GHz band presents a tougher engineering challenge because it requires line of sight and has a much shorter range that can be impacted by objects (including humans) between the terminal and the base station, as well as heavy rain.
Chau remarked that recent rainstorms in Hong Kong helped SmarTone to test network performance on the 28 GHz band in adverse weather conditions. The tests found that 28-GHz coverage shrinks considerably in rainy conditions, he said.
“The results will be very important in helping us fine-tune the network planning for the up and coming 5G rollout,” he said.
While SmarTone will conduct more tests – particularly when the typhoon season kicks in – to see how millimeter-wave attenuation can best be mitigated, Chau said the interim solution will be to engineer the network to ensure that attenuated 28-GHz connections will either hand over to the 3.5-GHz band or drop down a layer to the 4G network.
Chau also said that more work needs to be done on the network core, which hasn’t yet been upgraded to support 5G features like network slicing. “The standard for it has only just come out, so there’s still a lot of work to be done to define how to do network slicing.”
The cost of spectrum
SmarTone is ostensibly aiming to launch commercial 5G services sometime next year, though Chau cautioned that the timing will ultimately depend on the maturity of the 5G ecosystem in general and the availability of 5G devices in particular. He also said that 5G coverage at launch will be limited, depending on how many sites they roll out by then.
The timing of its 5G launch will also depend on when they acquire the necessary spectrum. Last week, the Office of the Communications Authority (OFCA) allocated 400 MHz worth of spectrum in the 26 and 28 GHz bands to SmarTone, HKT and China Mobile. OFCA intends to allocate a total of 4,100 MHz of spectrum in those two bands this year, and with no spectrum usage fees.
However, the 3.3-GHz, 3.5-GHz and 4.9-GHz bands haven’t yet been allocated. OFCA plans to auction 380 MHz of spectrum in all three bands later this year, but winning bidders won’t be able to use the spectrum until next year, which is why SmarTone (and other operators) can’t launch commercial 5G at least until then.
While OFCA has been lambasted by incumbent HKT for being slow to allocate 5G spectrum bands, SmarTone CEO Anna Yip said she was less worried about the timing of the auctions and more concerned with the high reserve price.
“The timing is okay, because even in China, you know, there’s a lot of hype about China [and 5G], but the commercial launch is not this year. There’s a lot of trials in different cities, but they’re not commercial launches. So everybody is looking towards next year,” Yip said. “What we have been lobbying the government about is really the [spectrum] reserve price, because we have to invest a lot for the rollout, and the reserve price in Hong Kong is staggeringly expensive, judging from the recent auctions.”
The other challenge with using the 3.5 GHz band is that it’s part of the extended C-band being used by satellite operators. OFCA has established exclusion zones in parts of Hong Kong where satellite teleports are located, which means 3.5-GHz licensees won’t be able to launch 5G in those areas.
“We still have to work with the government to try to address that,” said Chau, who urged the government to accelerate the process of relocating the teleports out of the zones and into less populated areas. “In the meantime, we are thinking about how can we use other frequency resources to try to at least to address that initially.”