White Paper: The Fifth Generation of Wireless Network Communications

As a critical but scarce resource in the 5G era, spectrum in three key frequency ranges is expected to deliver widespread coverage and support all 5G use cases: sub-1 GHz, 1-6 GHz, and above 6 GHz. The first two are often referenced as sub-6GHz. This is important as cellular data traffic continues to increase and enhanced mobile broadband is set to become the core consumer value proposition. Enhanced mobile broadband (eMBB) is one of three sets of use cases defined for 5G. As an extension to existing 4G broadband services, these use cases will be the first commercial 5G services to launch. However, they will go far beyond just enabling faster download speeds.

We expect both the United States and China to lead the first wave of 5G deployments. China will focus initial deployments in the C-band (3-5 GHz). The United States, on the other hand, will focus initial deployments on fixed wireless access through millimeter wave (mmWave) (above 24 GHz) frequency spectrum, as well as deployments in low bands (600 MHz).

We believe that in the long run, C-band spectrum may be challenged to deliver enhanced mobile broadband due to limited spectral efficiency and system capacity improvements, as well as the challenging 1ms latency. To support the requirements for wide contiguous bandwidths, mmWave will need to be considered.

In fact, with the current technical maturity and economic feasibility, a hybrid network is very likely. For instance, in major urban areas, mmWave is expected to be deployed for fixed wireless or hot-spot-like coverage, while sub-6 GHz is expected to deploy for coverage in suburban areas or small cities. 5G will continue to co-exist with 4G.

For deploying 5G, it’s important to understand key technologies such as the move from separate RRU and antenna systems to AAU with massive multiple-input, multiple-output (MIMO) integrating antenna elements and other active electronics. Antenna systems are expected to move from passive structures into active antenna units, containing electronics positioned directly at the antenna edge. The new active antenna systems are expected to move massive MIMO antenna to serve multiple users through multiple wireless channels, the so-called multi-user massive MIMO or MU-MIMO. We expect this to generate a high amount of data per antenna element through internal connections such as connectors and cables.

With the 5G new radio standard (NR), the key components may combine the RRUs and the antennas into an AAS.

Massive MIMO increases the capacity of a wireless network by as much as 50-fold. With more antennas, you also achieve better data rate performance and link reliability and more resistance to interference/jamming.

TE has years of high-speed interconnect, RF, signal integrity, thermal, rugged and mechanical design expertise. We also support a state-of-the-art global manufacturing footprint, delivering first-in-class components and solutions. In addition, TE offers an extensive interconnect portfolio that can address the design and manufacturing challenges of AAS. TE works in closely with our customer’s R&D departments on new designs.

Beyond datacom and wireless connectivity, TE is in many other markets — so as a customer, you benefit from our learning, advanced technology, and customer service. We are a global team with deep engineering talent, quality assurance in our factories, and strategic product development in our engineering centers. We have a big picture view and can understand your issues and help with next-generation problem solving.

The antenna is the most important element to communicate in a wireless system. TE has a broad design and manufacturing portfolio to create high-performance 3D antenna structures. The feeding point of the antenna in massive MIMO systems is often a board-to-board coaxial connector. TE has various solutions in its portfolio, of which the ERFV coax connector might give you a new approach on how to solve critical connectivity. The ERFV connector can be described as a one-piece connector, featuring spring forces to contact to the PCB board - providing very reliable connections and smoothing out the assembly tolerances. The filter, as the next important component in your design, is connected with a press fit ERFV coax connector to the antenna, and with a second coax connector to the amplifier board. The amplifier board collects all the antenna data. 

A huge amount of data must be transported toward the central processor. High-speed cable assemblies, such as TE’s Sliver interconnects feature high-design flexibility, low crosstalk, low insertion-loss performance, and enable high-speed data transport. In addition, the radio is part of the wireless network and needs an optical connection toward the network. TE’s high-speed I/O portfolio supports the EMI and thermal challenges. As an example, SFP, SFP28, QSFP, and QSFP28 are a good fit for radio applications. Those connectors, mated with an optical transceiver, might need to be protected for some environmental conditions, featuring TE’s FullAXS interconnects product portfolio. In addition, you may likely need to power for your system. TE's ELCON Mini connectors a powerful and reliable feeding point to the radio unit.

In 5G networks, we expect to see greater use of cloud-like concepts applied to both the radio access network and the core network. As an example, C-RAN (Cloud-Radio Access Network) will focus on both centralizing base band units (BBUs) and the adoption of cloud technologies such as virtualization. While OEMs can choose where to split the BBU functionality, this split will have a direct impact on the needed I/O bandwidth. TE’s I/O product portfolio supports 10G up to 400G interfaces, supporting a multitude of possible solutions the industry might need. 

However, by centralizing the BBUs at a C-RAN hub, a new layer is introduced into the network known as fronthaul. Fronthaul is the link between the BBU pool and the remote radio heads at the cell site or the small cell location. While fiber is the best fronthaul option as it delivers more bandwidth, likely there will always be a place for microwave links, depending on the location. To minimize the optical fiber connections, some radios can be daisy-chained by use of TE’s low loss, direct-attached copper (DAC) cables. This is a typical solution proposed by TE that can lower your thermal stress, thereby avoiding heat-generating components such as the optical transceivers.

For C-RAN, higher bandwidth connections are needed. In fact, high-frequency bands are increasing from around 1.8 Ghz to around 6 Ghz as well as the mmWave space of above 24 Ghz and up to 100 Ghz. This will be supported by new higher bandwidth transceivers, using new modulation schemes. TE Connectivity solves these challenges by offering a range of solutions including the integration of our high-speed I/O, power, socket, Sliver interconnects, board-to-board backplane cables, and ruggedized equipment.

The core network for 5G will need to rely on an extremely efficient cloud infrastructure. Cloud RAN (or centralized RAN) is a recent trend and operators in Asia Pacific are leading the way. As an example, Chinese, Korean and Japanese operators are aggressively rolling out advanced new C-RAN architectures. With C-RAN, the baseband processing for many cells is centralized. Benefits of C-RAN include improved performance due to the ability to coordinate between cells, and also cost reductions as a result of pooling resources. 

As data centers have escalated in size and power, a new trend has emerged: edge computing and edge cloud. Instead of data centers doing most of the computing, in this distributed computing paradigm, distributed device nodes such as smart devices (with embedded sensors) or edge devices may perform the work. Many believe that device design is shifting to include smart sensors with integrated microcontrollers, actuator-driver chips, and modules. This will change the role and requirements of the connectors and cables involved in a system.