The 5G standards body, 3GPP, is working to enable the virtualization and disaggregation of the radio access network (RAN). Analog Devices (ADI) and Intel said they are collaborating on a scalable platform to enable this new software-centric architecture.
The new radio platform combines ADI’s software-defined radio frequency (RF) transceiver technology with the high performance and low power of Intel’s Arria 10 field programmable gate arrays (FPGAs), offering developers a new set of design tools to optimize the designs of open-system 5G remote radio units (O-RU). In the proposed configuration, open RUs would connect to the network through open distributed units, or O-DUs.
Telecom operators are looking to reduce development time and cost-effectively implement new solutions to increase the performance and reliability of 5G networks. They have already started doing this by implementing open systems in their network cores and virtualizing functions, and now they want to do the same with their RANs. This is where the new radio platform designed by Intel and ADI comes in; it is supposed to reduce overall design cost and accelerate customer time-to-market without sacrificing system-level performance.
“ADI and Intel are developing an O-RU reference design to enable commercialization of hardware and software. Systems integrators and operators can port their code onto open processors and perform integration testing between the O-DU (which hosts the upper phy and Layer 2) and the O-RU (which contains the lower phy and RF subsystem),” said Joe Barry, ADI’s vice president of wireless communications.
5G and the next network
5G network operators would like to enable a new set of industrial services. One example would be to support the remotely guidance of field technicians equipped with augmented reality (AR) apps, another would be to support robotics.
As a practical matter, that’s going to require wireless access points. A 5G network will rely on new hardware and, in wireless communications, it will require the use of new antennas suitable for higher frequencies, on increasingly smaller cells. 5G New Radio (NR) bands include very wide RF channels, high transmit power levels and stringent emissions requirements. This combination pushes the radio performance envelope. 5G NR (New Radio) has been developed to operate in two distinct bands; sub-6 GHz (3GPP 38.104-5.2.1 FR1), and mmWave (3GPP 38.104-5.2.2 FR2). Despite actually running into the 7 GHz band, FR1 continues to be commonly referred to as the “Sub-6 GHz” band.
“Add higher frequencies of C-Band to the mix along with the requirement to co-exist with existing base station equipment and the path to RF success narrows significantly. A successful strategy we see is to pick a flexible radio architecture that meets these performance challenges while simplifying the RF front end to reduce power and cost,” said Barry.
One of the main challenges facing 5G technology is the need to support more connected devices capable of operating simultaneously at high transmission speeds. This requires extensive use of MIMO (multiple input multiple output) antennas, already introduced for the 4G-LTE network release. Relying more heavily on MIMO will allow the 5G networks to dramatically increase spectral efficiency.
5G requires not just MIMO, but massive MIMO; massive MIMO typically include 32 to 64 transmit/receive chains inside of a single radio unit (O-RU).
“With this density of radio signal chains, reducing size, weight, and power through the use of a low power radio architecture becomes critically important,” said Barry. He continued, “ADI’s software-defined transceivers enable deployment across all bands with lowest power consumption and the highest level of integration. Our 5th generation Zero IF (ZIF) transceiver platform addresses all 5G form factors from high power macrocells to high order mMIMO systems to low power small cells. Each generation of transceiver has included higher functionality, TRx chains, and bandwidth to meet the 5G challenges.”
In practice, extremely sophisticated algorithms manage the input and output signals of the antenna, making the (output) signals directional. The advantages offered by MIMO antennas lie in the possibility of communicating simultaneously with multiple users and multiple devices and in greater network throughput.
The design complexity challenges related to 5G systems are significant as the radio access networks are deployed in different geographies each with different spectrum and coverage requirements. “The addition of requirements such as increased bandwidths, mm-Wave, lower power, reduced latency, higher antenna count, dynamic spectrum sharing, massive MIMO, increased use of pico RRU and small cells all add to this complexity. To help our customers add more flexibility and openness to the 5G network we collaborated with ADI to enable the development of a flexible and highly integrated radio platform,” said Ronnie Vasishta, vice president and GM of the Network and Configurable Logic division at Intel.
Intel and ADI collaboration
The high-performance, O-RAN-compliant solution uses ADI software-defined transceiver with Intel’s Arria A10 FPGA. Pairing ADI transceivers with advanced digital front-end functionality with Intel’s FPGA technology will allow designers to customize frequency, band and power to achieve higher system performance at a lower cost.
FPGAs provide operators the flexibility to perform remote updates and upgrades with hardware programmability, enabling them to address changing requirements to fit individual business needs for specific 5G implementations.
“New features for new markets can be rapidly introduced and verified, accelerating time to market and adapting quickly to changing requirements without replacing the already installed equipment. This drastically lowers the OPEX. Additionally, different 5G configurations can use a common FPGA platform to be scalable and support different network partitions. FPGAs have been a part of every major inflection point in the wireless revolution, and 5G is no different. And, our FPGAs are part of a broader portfolio of technologies on offer from Intel to accelerate and optimize the rollout of 5G networks, including network optimized CPUs, Structured and Custom ASICs, Ethernet NICs, and FlexRAN software reference architecture,” said Vasishta.
The O-RU fits into ADI’s Radioverse ecosystem of solutions, tools, reference designs, software and technology resources. “It’s a commercial-grade resource that designers will use as a platform or reference design to build from or integrate directly into their next-generation small cell, micro or macro radio projects,” said Barry.
“Our collaboration with ADI allows us to drastically expedite hardware and software development for radio vendors and system integrators, said Vasishta. He continued, “the platforms support any frequency band between 600MHz and 6GHz, with either proprietary or open fronthaul protocols. It comes with a production-ready software/firmware framework to allow rapid development and deployment. It helps customers to adapt to their unique 5G network requirements faster and more economically. Installation of new infrastructure is expensive, and therefore, infrastructure must be utilized as much as possible by maximizing the length of time before an upgrade is required. As a result, network upgrades conducted in 2020 will have to withstand the expected hike in the magnitude and variety of network traffic through the next decade, making traffic density and throughput as critical as ever.