Macro LTE cells won’t offer big benefit
Operators are coming round to NEC’s way of thinking about LTE, according to Dr Sharam Niri, Director of Global LTE/SAE Strategy & Solutions at NEC Europe.
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“Two to three years ago when we told operators that LTE was going to require small cells, they said ‘no no no’. Then a year later they were saying they were surprised they hadn’t seen many small cell products from other NEPs. So either we are taking the wrong approach or the others [NEPs] are missing something,” Niri said.
Niri said that operators are now “starting to believe” NEC’s view that LTE will not map onto the macro 3G network, and will require a roll out of much smaller cell sizes of between 100-200 metres. “People have been underestimating the difficulty the different spectrum bands have presented. You can’t change the laws of physics,” he said. As evidence of this changing operator view, Niri said he “hoped” NEC would be announcing a major operator LTE trial within the next two weeks.
He admitted that the operators are asking for actual performance characteristics of NEC’s small cell LTE solutions. “They have seen that 2.6GHz doesn’t offer them much if they follow the 2.1GHz grid for 3G, but they require more solid data on what we are saying,” Niri said. “The challenge for us in this business is that we are saying something different from everybody else,” Niri added.
Andy Gothard, Director of Corporate Marketing, picoChip, which makes 3G femtocell chips and is developing an LTE solution, said that he hoped operators would see the benefit of building small first and then providing macro coverage. But he said that it appeared to him that operators were still planning to build “outside in”. “All the trials have been macro trials,” he said.
Many operators in Europe are considering a combination of LTE networks in one higher spectrum band, typically 2.6GHz, and one lower spectrum band – which could be re-farmed 900MHz or 1800MHz spectrum, or else new spectrum in the digital dividend band at 800MHz.
Indeed TeliaSonera’s Tommy Ljunggren said in his speech yesterday of digital dividend spectrum: “It’s not TV spectrum, it’s LTE spectrum.” And NEC itself has products that support the lower spectrum bands, but Niri is only keen to see them deployed in specific use cases – NEC is working at 850MHz in Japan and 800MHz in Argentina, and Germany has rural coverage requirements.
But Niri severely questioned the value of LTE at 800 or 900MHz in much of the rest of Europe. “Why would you do it?” he asked. “It’s not a useful solution in Europe – you don’t see the benefits of LTE – you can’t achieve much more throughput than with good HSPA coverage. So what are you offering?”
Niri said that NEC has form for being proved correct when it has gone against the herd. He said that NEC had counseled operators that MIMO plus 64QAM modulation in HSPA+ would not offer operators the increase in data throughput that the rest of the industry was expecting. Now most operators are skipping the idea of adding MIMO to HSPA, he said, as it has typically delivered only a 25-30% improvement, not the 100% they were offered.