Currently, billions of people, businesses, and devices are connected to the Internet. ICTs are transforming each and every aspect of our lives, from the way people interact and communicate to the way companies do business. People expect instantaneous high quality connectivity at all times. The COVID-19 pandemic has changed the way we deal with everyday life. Especially the Fixed Wireless Access (FWA) market has experienced tremendous growth as COVID has imposed the use of fixed broadband connectivity all over the world. This article provides more insight in the Ultra-broadband FWA using licensed mmW spectrum at 24/28GHz, its challenges and the main technologies that are currently behind this demanding race.
The current global trend in telecommunications is the worldwide allocation of harmonized frequency bands especially in higher frequencies (mmW) so that operators will be able to deliver ultra-broadband services to the millions of customers that constantly demand higher connectivity speeds. At the latest World Radiocommunication Conference (WRC-19) one of the main outcomes was the identification of additional globally harmonized frequency bands for the development of 5G networks with the co-existence to deployed networks remaining a strong requirement. More specifically, new allocations are taking place globally in mmW bands (above 24 GHz).
The opportunity of using wider channels at mmW bands makes these parts of spectrum very attractive to operators that want to deploy ultra-broadband access services. As an example, the FCC in the U.S. has opened up the CBRS band, 6 GHz, 24-47 GHz, and 60 GHz for possible FWA use. With 20x more spectrum possibly available for FWA, new proprietary & 5G FWA technologies, and government funding, the FWA market is poised for robust growth for years to come. It is very important that the new parts of mmW spectrum, which were identified during WRC-19 and are gradually allocated worldwide, are not exclusively tied to 3GPP. Other proprietary technologies can also be used for delivering broadband services using the large amount of contiguous spectrum. The multiple frequency bands that are allocated, serve the need to deliver both range and capacity utilizing the available spectrum assets. The perception behind the small ranges that can be achieved with mmW frequencies will be dismantled in the following paragraph of this article.
Broadband consumer networks are under the biggest change in history during the COVID-19 worldwide pandemic. Traffic that has normally been distributed among different clusters of network - enterprise, education, and public Wi-Fi networks - has now collapsed onto a single network access: fixed consumer broadband networks. With the rise of social distancing most of the internet users have shifted to using the offered services from their residences (teleworking, remote education, streaming etc.). This has caused significant changes in traffic composition, and introduces new challenges for network operators worldwide who are taking up the challenge of providing faster broadband to homebound customers during the pandemic.
Once again the rural, semi-rural and underserved areas are in the epicenter during these times of uncertainty. Urban areas have already deep & advanced network infrastructures and a variety of fancy options to choose from when it comes to connect to the internet. Even with the amazing speeds and services that 5G is offering, it seems that it is too expensive to reach beyond the very dense urban areas.
In the United States it is widely accepted that FWA will bring broadband to the masses outside metropolitan areas. That's absolutely not going to happen without substantial government subsidies. The good news is that in many countries there are government initiatives that aim to strengthen the underserved areas. In USA, the Rural Digital Opportunity Fund (RDOF) is the Commission’s next step in bridging the digital divide to efficiently fund the deployment of broadband networks in rural America. Through a two-phase reverse auction mechanism, the FCC will direct up to $20.4 billion over ten years to finance gigabit speed broadband networks in unserved rural areas, connecting millions of American homes and businesses to digital opportunity.
Besides the aforementioned RDOF in the United Stated there are many other initiatives for boosting broadband connectivity, either on a national or on a continent level. One the most relevant examples is the European Gigabit Society initiative. One of the objectives of this initiative is that all European households should have access to 100 Mbps connections by 2025, with the possibility to upgrade those networks to reach 1 Gbps. These directives will be materialized by using a bouquet of access and transport technologies.
5G FWA is considered as a candidate technology in order for the above initiates to be able to deliver the required capacities, but this comes at a cost. 5G cells are denser than its 4G counterparts and their respective range is degraded to the order of 1,500 ft. This means more CAPEX and OPEX for the network operators. Furthermore connecting remote rural locations will require additional investment in fiber and microwave links that will expand the total costs.
The truth is that rural areas are at the bottom of the list of priorities for every major communications carrier. The money just isn't there. They will simply invest where the people are. The revenue is in the dense populated areas. 3GPP biased operators will spend tens of billions per year building out 5G infrastructure and will prioritize locations that will yield the best returns, hence the urban centers. Areas with lower population density will need PtMP FWA technologies that can deliver long range connections with the terminal stations and sufficient ultra-broadband capacity.
Intracom Telecom's proposition for delivering ultra-broadband FWA in remote locations is called WiBAS™, a field proven Point-to-Multipoint (PtMP) technology operating in the mmW spectrum that can deliver several 100 Mbps per user, with extended coverage - more than 3.7 mi cell radius - serving the distant sub-urban & rural area residences. WiBAS™ addresses various segments of the FWA market from simple pure ultra-broadband residential connectivity up to backhauling of high definition surveillance networks. The figure below summarizes the main applications of the WiBAS™ product line.
Intracom Telecom, a global telecommunication systems and solutions vendor, offers its advanced 5th generation PtMP radio family, the WiBAS™ G5, that operates in TDD and FDD area licensed microwave spectrum, to contribute to FCC’s goal in bridging the digital divide in rural and sub-urban areas in USA. Intracom Telecom’s ability to fulfill the need for high quality broadband FWA and its successful track record in implementing FWA networks across the globe constitute the perfect combination in helping operators and ISPs to claim compliance up to the Gigabit Tier of the Rural Digital Opportunity Funding (RDOF).
As the Federal Communications Commission (FCC) has underlined, broadband access is no longer considered a luxury, but a critical component in everyday life for all Americans, highlighting the need to encourage rural and sub-urban USA areas. The WiBAS™ G5, is operating at the frequency bands 24.25-29.50 GHz and achieving throughput that exceeds 550 Mbps per subscriber with channels of 100 MHz width. With the use of 2x100 MHz channels each subscriber shall be served with Gigabit Tier throughput in the downlink, and 500 Mbps in the uplink.
Based on the most advanced technology in the market, the WiBAS™ G5 evo-BS, has an exceptional deployment flexibility serving anyone within a large area footprint, and it supports a variety of sectoral antennas ranging from 90°, to 180°, and to full 360° coverage. Due to its compact size this PtMP base station is not demanding heavy telecom infrastructures. At the same time, the new WiBAS™ G5 Connect+ is an advanced terminal station for operators that want to be worry-free and are in need of high quality hardware, as it is remarkably easy to install.
WiBAS™ has become the preferred alternative to fiber access solutions in Europe, Southeast Asia, Middle East and Africa. The company's recent and successful FWA network deployments are with leading operators and ISPs in Italy, Spain, Indonesia, and South Africa. More specifically in Italy, two major operators have decided to invest in WiBAS™ and the mmW band for their FWA offering. Open Fiber, one of the largest fiber network providers in Italy selected WiBAS™ for the Rural Ultra-Broadband project of the "digitally underserved" areas of the country. The ambitious plan of Open Fiber foresees to deliver Ultra Broadband services in about 20 million households in each of the 20 Italian Regions, in remote and rural areas or areas with scattered houses. Open Fiber has received government funding by winning 3 public tenders that were issued by Infratel which is an in-house company of the Italian Ministry of Economic Development. All this as a part of the "Italian Strategy for Ultra-Broadband" which is a public initiative to support the development of ultra-broadband networks in Italy. The goal of this initiative was to assure committed 30 Mbps access speeds for all Italian households and 100 Mbps peak to 85% of them.
Besides operators that receive government funding though public initiatives, there are also cases of solely private funded carriers that invest their equity to technologies they trust. WiBAS™ was also the selected solution by EOLO SpA, an Italian telecommunications operator focusing on ultra-broadband in sub-urban and rural areas.
EOLO is currently providing FWA services to over 500,000 active subscription customers in 6,000 municipalities throughout Italy. EOLO initially has invested in a FWA network operating in the unlicensed 5 GHz band. The advertised capacity was 30 Mbps. With the capacity demand increasing exponentially, the 5 GHz network and its narrow channels as well as shortage of uplink capacity, proved insufficient to deliver the extra boost that was needed. As a result EOLO decided to invest in the mmW band of 28 GHz and after rigorous testing they selected WiBAS™ for the solution, managing to advertise 100 Mbps service for the same monthly fee. The installation of the solution is part of EOLO's current extensive investment in its fast expanding network in the whole of Italy, aiming at becoming the first provider of ultra-broadband services to residential and SME subscribers in the country's suburban and rural areas.
It is well accepted by the telecommunication industry, and by all the major operators, that 5G cannot deliver the huge end-user speeds at long ranges when operating in the mmW bands. There are various articles and testimonials about current commercial 5G deployments that mention an average cell radius coverage of maximum 1,000 ft. This implies that 5G requires cell sites that will be closer to each other.
This fact has significant implications on the total network architecture complexity and rollout.
To demonstrate the vast difference between 5G coverage and the purpose-built WiBAS™ FWA technology that is operating in the mmW band, a coverage/capacity case study is presented in a certain polygon area in suburban Chicago Illinois. The total selected coverage area is 177 mi2. Table below shows the main assumptions that were used for this exercise.
| Coverage Area: | 177 mi2 |
|---|---|
| Total number of Cells: | 8 |
| Total number of Sector: | 32 |
| Total Spectrum: | 200 MHz TDD (2x100) |
| Polarizations: | Vertical & Horizontal |
| Terminal Station: | 1 ft antenna |
| TDD Split: | 2:1 (DL:UL) |
| Coverage Cell Edge Target Link Availability: | 99.95% |
| Rain Rate: | 40 mm/hr |
| Availability models according to ITU | Yes |
The result of the coverage analysis is that WiBAS™ G5 evo-BS need 8 cell sites to cover the entire area with a maximum cell edge range of 3.7 miles. The downlink coverage map is presented in Figure 1. The different colors refer to the different modulations that the respective terminal stations are operating. It is important to note that most of the target areas can be serviced with links of at least 64-QAM. This can be interpreted in connection speed.
The terminal station in this study can achieve at the cell edge more than 300 Mbps in the downlink and more than 100 Mbps in the uplink direction. The total capacity that is offered by these 8 cell sites is approximately 20 Gbps.
Assuming that the average 5G cell site operating in the mmW band (28 GHz) achieves a maximum cell edge of around 1,600 ft. then we can derive that the same area that is depicted in Figure 1 needs a total of 860 cell sites to provide the same amount of coverage as the WiBAS™ system. What is the impact of this huge difference in the number of required cell sites to cover this certain polygon area? The following paragraphs summarize the major metrics that are significant for operators when it comes to select the technology they are willing to invest.
The multiple connectivity options in the 3GPP architecture for 5G have created several possible deployment alternatives and different levels of complexity. It is not only the major architectural components that are depicted in Table 1 that need to be considered by the telecommunication carriers. Network operators that deploy 5G must be able to support user equipment, radio network, core network and management products that are manufactured by a multitude of device and network equipment vendors. 3GPP biased operators will build on the existing 4G infrastructure and deploy the initial connectivity options before moving on to the standalone NR architecture defined by 3GPP Release 15. The above complexity is increased by the number of intermediate components/cells that will be used in dense 5G networks as well as the number of end user services that the carrier wishes to deliver. Wireless ISPs and other operators that have not invested in the past in the 3GPP pool, will be more reluctant to bet their capital in a technology that mandates so many prerequisites before delivering simply FWA services to the end customer.
Deploying a Fixed Wireless network is vastly dependent on the transport network pipes that will carry all the data towards the core network. The higher number of cells create a larger complexity and cost for the operator. Dense 5G deployments lead to the increased need for backhaul for so many cells so close together, employing both fiber and high capacity wireless technologies in a mesh topology. The fewer cell sites that are deployed with WiBAS™ will require a leaner and cost effective transport network.
One of the little secrets of 5G is that the base stations consume a lot more power than the previous generation technologies. The power consumption of a 5G base station is approximately three times that of its 4G LTE predecessor. The major reason for this difference is because of the massive antenna arrays (MIMO) used for the next generation technology. Massive MIMO increases the "power amplifiers" and "analog-to-digital paths" required, as well as overall digital circuitry in the units. This is translated to increased kilowatts of power that is needed per 5G cell site. Technologies that can cover the same area with fewer cells will result in optimized energy bills towards MNOs.
| WiBAS™ | 5G | |
|---|---|---|
| Terminal Stations (CPEs) | Terminal Stations (CPEs) | |
| Base Station HUB | Small Cells | |
| Ethernet Aggregation | Macro Base Station Sites | |
| Backhaul | Fronthaul Network (C-RAN) | |
| IP Core / OSS | Backhaul Network | |
| 5G Core |
The additional frequency bands that were identified by WRC-19 for the deployment of 5G networks are not exclusively tied to 3GPP. Depending on the country and the relevant regulatory bodies there are cases where spectrum is allocated for both IMT-2020 (5G) use and other fixed wireless technologies. This means that there will be cases of coexistence between 5G and other proprietary networks that will operate in adjacent bands.
In the cases of unpaired spectrum allocation the network equipment operate in Time Division Duplexing mode (TDD). To utilize this spectrum most efficiently and avoid interference issues, all TDD networks, legacy or new ones, operating in the same frequency range and within the same area have to be synchronized.
Base stations need to transmit at the same fixed time periods and all devices should only transmit in dedicated time periods. Full synchronization of adjacent TDD networks requires the operators to use a common frame start reference (e.g. GPS), common frame length and common frame structure (i.e. TDD DL/UL split ratio).
WiBAS™ G5 evo-BS base station is fully compliant with the aforementioned requirements for coexistence of different networks operating in the same frequency band. The base station is using GPS signal to synchronize the receive/transmit timing. The frame length and structure of the WiBAS™ G5 evo-BS does not violate the 5G framing specifications. Both are user configurable to meet the frame length and TDD DL/UL that is selected by adjacent operators in a national or international level.
The ICT industry is going through a major transformation. Besides the exponential annual growth of end-user capacity demand, the recent COVID-19 pandemic has changed the ways that people work, communicate, educate and entertain. There is a major shift towards fixed-access applications. The wireless arena is always trying to catch-up. More spectrum is allocated worldwide especially in the mmW bands in order to make use of the wider channels and provide ultra-broadband speeds. With the remote and underserved areas being at the epicenter of the digital-divide, there are a lot of public initiatives that provide funding to the carriers that wish to invest in technologies capable of reaching these sensitive part of the population with ultra-broadband speeds.
WiBAS™G5 broadband Fixed Wireless Access solution operating in the 24/28 GHz - mmW bands bridges perfectly the broadband gap between urban and rural areas and becomes the perfect solution for operators that do not want to invest in the complex, dense and power hungry 5G technology. WiBAS™G5 evo-BS is capable of delivering ultra-broadband speeds to terminal stations that are located at cell edges of more than 3.7 miles. Intracom Telecom’s ability to fulfill the need for high quality broadband FWA and its successful track record in implementing FWA networks across the globe constitute the perfect combination in helping operators and ISPs to move closer to the 1 Gbps per user era.