The estimated transport capacity requirements of 5G Mobile Base station sites, which include co-located 2G/3G/4G/4G+ systems, will inevitably increase in the short to mid-term future to above 10 Gbit/s, given the progressive allocation of more spectrum to 5G systems and the gradual adoption of capacity-enhancing 5G-Advanced technology. Additionally, mmWave Fixed Wireless Access (FWA) systems, such as Intracom Telecom's WiBAS™, also require 10 Gbit/s or more for the backhaul needs of multi-sector FWA base station sites. These trends impose higher demands on the transport system links deployed between the access sites and the core network locations.
Wireless transport systems are, and will continue to be, a key alternative and an indispensable complementing solution to the use of optical fiber links.
Wireless transport system manufacturers employ several ways to increase the capacity of their radio systems, such as introducing support for larger channel sizes per link or using multiple links, the capacity of which is seamlessly combined via link aggregation, as well as increasing the spectral efficiency of their radio systems.
Using larger channel sizes or aggregating multiple links correspond to using more spectrum. Increasing spectral efficiency corresponds to using the spectrum more efficiently by squeezing more capacity out of it. Spectral efficiency is related to the capacity achieved by the radio system for a particular channel size and is a key counterbalancing trait to the “brute force” approach of the spectrum-hungry methods.
Regulators have responded to the market needs by increasing the channel size allocation applicable to the traditional fixed transport service-related microwave (MW) frequency bands, which typically occupy the spectrum up to 38 GHz. For example, allowing 112 or 224 MHz channel sizes in MW bands where channel sizes up to only 56MHz channel sizes were allowed in the past. However, the need for higher spectral efficiency of transport wireless systems is inescapable, as the capacity requirements grow continuously, but the available overall useful spectrum remains the same, or can even be reduced by allocation of some MW spectrum bands to uses other than fixed service.
While extending the useful spectrum for transport applications to higher frequencies (above 80 GHz) is under research, still suffering from link-range/availability drawbacks, the currently “technologically mature” part of the spectrum is becoming highly contested by multiple Communication Service Providers (CSP), and as a result regulators are forced to allocate multiple channels or larger channel sizes more sparingly.
The operators enjoy an economic benefit when deploying high spectral efficiency technology, due to the smaller channel size and/or fewer channels they need to license. Furthermore, some regulators provide extra license fee-related incentives for operators that deploy technology with high spectral efficiency, such as XPIC configurations.
These trends place particular importance on increasing the radio spectral efficiency to obtain the maximum possible capacity performance with the minimum possible channel size. Ways to improve spectral efficiency include, higher-order modulation formats, use of XPIC, MIMO, use of low overhead error correction schemes, spectral shaping for maximization of a channel’s useful bandwidth, traffic compression, using higher Class, more directional, antennas and others.
For example, the XPIC technique enables utilizing simultaneously both the horizontal and vertical polarizations of the allocated frequency channel, effectively doubling throughput and spectral efficiency. There are various cost, system gain, hardware and other technology complexity trade-offs associated with the application of the spectral efficiency-enhancing techniques. The research and evolution in this field is continuous and intensive.
Given the optimum practically achievable level of spectral efficiency, it is still necessary that more spectrum has to be employed to reach the desired link capacity levels. Using larger channel sizes is preferred to using multiple channel sizes if this also means that less HW/discrete radio units are required to be deployed. However, sometimes this is not an option since the maximum channel size in the band of operation may not offer enough capacity, so more than one channels have to be aggregated. One way to avoid the deployment of multiple radio HW/link instances is to integrate more than one transceiver/carrier within a single unit. This has installation space, speed and simplicity advantages as well as power consumption advantages.
When selecting larger or more channels in a particular band is not feasible or economically favorable, then combining links of radios operating in two or more different frequency bands, sometimes referred to as Dual Band or Multi-Band, can allow the cost-efficient use of more spectrum for the generation of the required transport capacity. Especially if one of these bands is the E-Band, this solution proves to be an excellent option, which can provide the simplest multilink configuration, since the largest part or all the required capacity can be contributed by a single E-Band link component, while the lower frequency microwave link(s) of the configuration provides a high availability, necessary capacity component. Since E-Band spectrum is usually priced by regulators very favorably compared to MW spectrum, an E-Band-based dual band transport solution can many times be the simplest and the most cost-effective solution for high-capacity wireless transport links[1].
Finding the right balance between cost and complexity is key to the selection of the capacity-enhancing approach that can be applied in an optimum way for a particular transport link’s capacity, range, and availability requirements[2].
Intracom Telecom’s new MW and mm-Wave radios lead in spectral efficiency and capacity Intracom Telecom’s MW and E-Band radios, already widely deployed in Mobile or Fixed CSP networks, are ideal for 5G-era transport / xHaul applications, as they are at the forefront of performance in terms of link range, spectral efficiency, and operational flexibility. Intracom Telecom presses on with the evolution of its leading series of UltraLink™-GX80 E-Band radios and OmniBAS™ MW radios by pushing the spectral efficiency barriers yet further.
The new UltraLink™-GX80 Advanced is the highest-throughput single-transceiver E-Band radio in the market delivering up to 15 Gbit/s full duplex data traffic rate in 1+0 link configuration by employing 512-QAM modulation of in a single 2000 MHz channel. It builds and improves on the leading system gain of the field-proven UltraLink™-GX80 radio enabling longer and more stable high-capacity radio links.
UltraLink™-GX80 Dual is a high-performance dual-transceiver E-Band radio delivering up to 15 Gbit/s full duplex throughput with double the spectral efficiency of a single-transceiver E-Band radio. It achieves a particular multi-gigabit/s capacity using half the channel size employed by a single-transceiver E-Band radio, 1000 MHz for 15 Gbit/s, while having the same simple installation requirements, form-factor and weight as the UltraLink™-GX80 Advanced.Both radios feature an embedded Ethernet Bridge that offers advanced Carrier Ethernet services over multiple 10GbE user interfaces and supports the highest accuracy packet-based synchronization protocols to fully address the requirements of 5G networks. Furthermore, they are SW upgradeable to support IP/MPLS functionality bringing the benefits of IP networking to the edge of the network without requiring additional dedicated CSRs. The UltraLink™-GX80 E-Band radios can be seamlessly combined, using L1-link aggregation, with the OmniBAS™ MW all-outdoor radios, OmniBAS™-BX or OmniBAS™-BXd, using a single Dual Band antenna to offer fully outdoor Dual Band configurations delivering up to 15 Gbit/s throughput and extended range.
OmniBAS™-BX, the well-established portfolio of all-outdoor radios of the OmniBAS™ Point-to-Point MW family, covers a wide range of MW frequencies from 11 GHz to 38 GHz. It supports market-leading modulations up to 4096-QAM and channel sizes up to 112 MHz per unit, to offer 1 Gbit/s or 2 Gbit/s using one or two units in XPIC 2+0 configuration.
OmniBAS™-BXd, the new generation of dual-transceiver all-outdoor radios features a novel design to support 2 x 112 MHz channels in a single compact unit at frequencies 13-38 GHz, while maintaining the high system gain required for long range/high availability links. It can be flexibly configured for 1+0, 1+1, 2+0 or XPIC 2+0 link operation offering MW radio capacity 2 Gbit/s using just one unit.
Both OmniBAS™-BX and OmniBAS™-BXd radios employ advanced radio and traffic processing functionality to deliver exceptional MW radio performance and constitute the perfect match to UltraLink™-GX80 Dual / Advanced in Dual Band configurations up to 15 Gbit/s full duplex throughput.
As an example, figure below depicts an indicative Dual Band link setup consisting of an UltraLink™-GX80 Dual and an OmniBAS™-BXd radio. As both radios support 2+0 XPIC/RLA operation in a single unit, they achieve the maximum spectral efficiency, while delivering multi-gigabit/s throughputs, with minimum hardware. Such a solution not only minimizes the number of radio units that need be installed on the pole but also reduces the spectrum fees that need be paid, thus facilitating substantial CAPEX and OPEX savings to CSPs.
As the requirements for transport capacity continue to grow, wireless technology evolves to satisfy it in an efficient way, ideally complementing optical fibre technology. The new Intracom Telecom MW and E-Band radios can deliver up to 50% improvement on throughput, while optimizing licensing costs and minimizing installation space and complexity.