Qualcomm bids to stay at the heart of 3GPP standards
Last week we focused on how the R&D lines between 4G and 5G are blurred – many technologies which are likely to end up in the 5G standards are already being trialled and even deployed as part of the evolution of LTE, creating a continuum which may save operators from another big bang upgrade.
And the announcements just keep coming, only stimulated by the start of the World Radio Conference 2015 this week, with hopes for some pointers on 5G spectrum; and by the kick-off of the 3GPP standardization process.
Qualcomm, of course, has the critical challenge of trying to get its technologies into the heart of those standards as it did in 3G, CDMA, and even, to some extent, LTE. This week, it has been outlining the ideas it will submit for new 3GPP air interfaces for 5G. Proposals for wave one of these standards are due in March, with the specifications expected to be finalized in late 2018, mainly targeting conventional sub-6 GHz spectrum bands. Those will be followed by a second wave, which will reach further into new bands, such as millimeter wave, and more abstruse technologies. That round of standards is expected in late 2019.
“Our vision for 5G is vast,” Qualcomm said in its statement. “Much more than just faster peak rates, we envision 5G will be a unified, more capable platform that will connect new industries and devices, enable new services and empower new user experiences. A completely new kind of network that will take on a much bigger role than previous generations-creating the connectivity fabric for everything.”
But behind the grand words, John Smee – a senior director of engineering at Qualcomm Research and head of the firm’s 5G technical work – admitted: “We are designing a network for a future we don’t know.” He told EETimes: “It’s like our work on 4G, 10 years ago when people carried flip phones to the meetings and thought about a network capable of downloading video.”
There is no consensus in the industry on whether 5G will require one or multiple new air interfaces to support its many proposed use cases (or whether it can make do with evolutions of existing ones, as some argue). Qualcomm is proposing a family of interfaces, mostly based on OFDM, but with one exception. For IoT transmissions with low data rate and signalling, but high requirement for reliability, it would use the non-orthogonal RSMA (resource spread multiple access) in low spectrum bands. A new multiplexing technique would allow traffic requiring very low latency, as in some IoT services, to take priority automatically and to use RSMA.
RSMA was developed by Qualcomm and may be the firm’s latest bid to dominate at least one strand of 5G in the way it did with CDMA-based networks. The technology uses time and frequency spreading and overlaps users in a way that aims to improve network efficiency and power consumption. I can support mobility and downlink meshing, as well as network-assisted mesh on the uplink.
Qualcomm has also invested heavily in OFDM technologies since it became clear that 4G would move towards this modulation and away from CDMA. It acquired companies like Flarion for their OFDM smarts and patents and became a significant contributor to the LTE roadmap. Multiuser massive MIMO is also an important element of its 5G ideas.
Of its overall submission, Smee said in the interview: “It’s not a new waveform but an expansion of OFDM for wider use cases with a family of numerologies with scaled tone spacing.”
He added: “No one numerology fits all use cases, but a family of three or four provides a checkerboard of design parameters.” This then allows systems be optimized for different cell sizes and frequency bands, a step towards the infinite flexibility which most envisage for a 5G network which will have to adapt to many different applications and business models, some as-yet undefined.
Qualcomm summarized this approach, in its official statement, as “a unified air interface with optimized OFDM-based waveforms and multiple access, with a flexible framework that can scale from low spectrum bands to mmWave, from macro deployments to local hotspots, and will support licensed, unlicensed, and shared licensed spectrum from the beginning … For targeted use cases such as sporadic uplink traffic from battery-powered IoT sensors, the use of non-orthogonal RSMA helps further reduce device complexity.”
As well as the air interface, it is developing and submitting technologies in two other key areas. One is new multi-connectivity technology to support simultaneous connectivity and aggregation across 5G, LTE and WiFi technologies with a multi-access 5G core network. This will also support device-to-device communications, managed multihop communications and relays, all aiming to extend network coverage.
The second is a flexible network architecture that will enable 5G and over-the-top providers to create new services very quickly, to “meet the extreme variation of 5G use cases and scale all the way from low cost hotspots to carrier grade wide area deployments”.
The company said its architecture would allow connectivity to be “jointly configured end-to-end-across the unified air interface, radio access network and core network-using specialized network functions optimized for specific services. The new architecture will deliver mobility-on-demand by distributing network functions at the core or edge of the networks based on the service requirements and device context, while taking advantage of emerging virtualization technologies to generate network slices optimized for the target services or deployment types.”
Qualcomm, like others, wants the 3GPP to define first wave 5G standards below 6 GHz in both licensed and unlicensed spectrum, and then move on to millimeter wave – also in licensed and unlicensed – and a new 5G anchor network.
Meanwhile, Nokia became the first non-Chinese vendor to sign a 5G-related memorandum of understanding (MoU) with China Mobile Research Institute (CMRI). This is part of a wider one-year framework deal between the two firms, valued at more than $1bn, which also involves TD-LTE and VoLTE roll-out.