5G: Indoor Network
Sumber: https://www.ericsson.com/en/reports-and-papers/white-papers/bringing-5g-networks-indoors
Dengan jaringan 5G yang sekarang mengudara dari operator Tier Satu di seluruh dunia, ada semangat yang luar biasa dengan teknologi baru ini dan apa artinya bagi masa depan. Optimisme seputar 5G ini dibenarkan dan diharapkan mengingat berbagai kemampuan baru dan lebih baik termasuk peningkatan besar-besaran dalam kecepatan broadband, latensi sangat rendah, dukungan perangkat IoT dalam jumlah besar dan kasus penggunaan penting yang memerlukan tingkat keandalan dan keamanan tertinggi. Beberapa keuntungan ini dapat dicapai dengan peningkatan perangkat lunak dari sistem LTE yang ada, sementara yang lain terkait langsung dengan spektrum baru, teknologi radio, dan arsitektur penyebaran.
Untuk jaringan Indoor (dalam ruangan), 5G akan memberikan pengalaman baru bagi konsumen, kemungkinan baru untuk efisiensi operasional dengan IoT, otomasi industri, dan layanan komunikasi baru. Namun ada banyak pertanyaan di industri seputar tantangan dan peluang unik dalam menghadirkan 5G indoor.
5G introduces both evolutionary and revolutionary changes compared to previous generations, resulting in questions related to how best to bring these new capabilities to indoor spaces. These questions are in three different areas:
5G memperkenalkan perubahan evolusioner dan revolusioner dibandingkan dengan generasi sebelumnya, menimbulkan pertanyaan terkait cara terbaik untuk menghadirkan kemampuan baru ini ke ruang indoor. Pertanyaan-pertanyaan ini ada di tiga bidang berbeda:
- What 5G use cases are applicable indoors?
- What spectrum can be utilized?
- What are the challenges and benefits of different indoor network architectures: DAS, distributed radio, small cells?
This white paper will explore these questions, compare different options available to network operators for deploying 5G technology indoors, and provided recommendations on the optimal solutions.
5G indoor use cases
The introduction of 4G LTE has revolutionized mobile broadband networking. Radical changes in consumer society have been enabled by massive increases in throughput and capacity, enabling entire new ecosystems around the smartphone app economy. In the same way that it was impossible to predict the transformation enabled by 4G, the industry is on the verge of an even more fundamental transformation with 5G. In addition to advances in multi-Gbps mobile broadband, 5G will introduce fundamentally new architectures to support Massive IoT and Critical Realtime IoT applications. Ericsson has divided 5G use cases into three primary categories, of which only a subset are relevant indoors.
Enhanced mobile broadband
Enhanced mobile broadband is the step change in bandwidth coming from 5G that will enable new user experiences that benefit from that increase. While 4G LTE is evolving and offers speeds over 1Gbps with advances such as LAA and Massive MIMO, 5G will enable bandwidths up to 10 and 20 Gbps depending on available spectrum. In a building, this will enable new Augmented Reality, Virtual Reality and Mixed Reality applications delivered to wireless devices which has application in manufacturing and entertainment. 5G will also enable wireless streaming cameras with 4K and even 8K resolution. This could enable wireless security cameras, streaming of high-resolution video for training or education, or in more public spaces, upload of video to social media. These use cases are all relevant in indoor environments.
Peak data rates and capacity for mobile broadband are constrained by the amount of RF spectrum available – although 5G can use existing spectrum more efficiently than LTE in some cases, improvements in mobile broadband speeds would be constrained by available spectrum. Fortunately, national regulatory agencies around the world have responded to this need.
Massive IoT
Massive IoT is the range of use cases that rely on broad, low cost coverage to carry very small data messages from thousands of devices. These are not time critical messages but rather insensitive to small delays, instead prioritizing cost and battery life.
Primary examples of Massive IoT are for smart meters, sensor networks and tracking. All three of these use cases could be applicable in buildings. Some use cases are identified below:
- New smart building technologies to track and manage the indoor environment - temperature sensors, motion sensors, light sensors all tied to the HVAC units, automated window shading and lighting systems
- Object tracking – a hospital, for example, tracking beds, equipment carts, individual portable machines. A stadium can track fresh beer kegs (and their temperature), lines at concessions and restrooms, and other opportunities. Other examples include an airport tracking wheelchairs, carts, and accessibility vehicles
- Tracking scanners, devices, and other equipment and logistic applications in indoor environments like factories or distribution centres
Massive IoT applications are beginning to be deployed today with 4G LTE technology. The LTE standard contains specific techniques to enable low-bandwidth, very low power devices to coexist in the same network as high-performance smartphones. 5G builds on these LTE capabilities, enabling even higher scalability of device density.
Critical IoT
Critical IoT, unlike Massive IoT, implies extremely high reliability, exceedingly low latency and 99.999% (5 nines) availability. This is where 5G is really separating itself from 4G LTE.
Use cases being tested in this area include remote control of robotic machinery and automated vehicles. Labor regulations and industry standards place extremely stringent requirements on these safety-critical control systems to ensure worker and public safety. 5G networks will achieve end-to-end latencies on the order of 1 millisecond.
To achieve the reliability, latency and availability expected with these new use cases, networks must evolve to incorporate new technology coming with the 5G standard in 2020. Specifically, the 5G NR standard with Stand Alone core network.
Some of the low latency aspects will also come from new distributed architectures, where some control and processing occurs at the edge of the network. For an indoor application, this will require a local node either on premise or within a very short distance.
As discussed above, the nature of the 5G use case desired is critical to understand before attempting to define the technical requirements of the network. Each different use case has different implications for the spectrum required and the architecture required to support.
5G and Spectrum
Several new frequency bands have been added to the 3GPP licensed spectrum over the years, and there is a direct correlation between spectrum and bandwidth available for services. To understand this, we can look at the history of cellular technology. Originally, low-band (< 1 GHz) bands dominated which were optimal for wide-area voice and SMS coverage. Operator 1G and 2G networks were universally deployed in these low bands which can be characterized as very broad coverage with limited bandwidth. Operators typically had 10 or 20 MHz of spectrum available in any given market with which to offer services.
With 3G and 4G, many mid-bands (1 – 6 GHz) were added in order to improve mobile broadband. These bands have shorter wavelengths and thus shorter reach, but larger bands of spectrum are available. Recently new spectrum sharing schemes including LAA and CBRS have been introduced in these middle bands. When operators can leverage these new bands, total bandwidth available for end-user services increases significantly. An operator with LTE Advanced service leveraging carrier aggregation across multiple licensed bands plus LAA can offer peak user bandwidth in excess of 1 Gbps.
With 5G, in addition to even more mid-bands, high bands (6 – 60 GHz) are being added which introduce entirely new challenges. mmWave spectrum is getting significant attention because of the extremely high bandwidth available to deploy services, leading to multigigabit speeds for users. The challenge with this high band/mmWave spectrum is that the wavelengths are extremely short and thus the radio waves do not propogate through external or even internal walls.
Application and recommendations
With such a variety of use cases, technology choices and deployment architectures, it can be bewildering to sort out which are the optimal arhictectural choices for introducing 5G indoors.
In an indoor environment there are unique considerations. Ericsson recommends a design and deployment approach tightly tied to the intended use cases for the indoor deployment. We take each use case category below.
Mobile Broadband use cases
Although Mobile Broadband is only one of the use case categories supported by 5G, we expect it will be the dominant requirement for initial 5G indoor deployments. In order to enable 5G mobile broadband use cases, there must be sufficient end user bandwidth. Ericsson recommends the following for indoor 5G mobile broadband deployments.
Wide channel bandwidths (up to 100 MHz) Higher order MIMO (e.g. 8x8) Coordinated RAN with outdoor network to reduce indoor dominance requirements; indoor and outdoor networks complement each other High SINR with “good RF” high throughput To achieve these network characteristics,a “deep layering” approach is recommended, with multiple mid-range (1 – 6 GHz) bands layered and multiple MIMO layers per band across all available spectrum. Layering would easily be extended into unlicensed and shared-access spectrum (such as LAA and carrier aggregation with CBRS). Innovations such as Cell Border Shifting can help minimize inter-cell interference and “dead zones” of low performance. To meet these specific requirements for 5G enhanced mobile broadband (eMBB), Distributed Radio architectures have advantages compared to traditional distributed antennas (DAS) or uncoordinated small cells (femtocell) architectures.
Figure 2: A deep layer approach in a standard enterprise environment Figure 2: A deep layer approach in a standard enterprise environment
Features Features Distributed Radio DAS Uncoordinated Small Cells Cost of scaling Low cost scaling with IT-grade cabling High cost scaling with higherorder MIMO High cost to scaling Capacity Flexible expansion in centralized baseband Densification of capacity per square meter requires expensive installation of headend equipment and splitting of equipment throughout the venue Fixed maximum capacity per area Mid-band capabilities Low, medium and high-band availability Limited mid-band capabilities (3.5GHz) Limited to femto chipset Flexibility of reconfiguration Flexible capacity reconfiguration Highly inflexible and expensive to reconfigure Inflexible Evolution to mmWave Supported No evolution to mmWave Inflexible evolution, capped by femto chipset limitations Additional functionality RF-agnostic out to very edge, avoids coax limitations Massive IoT use cases
Massive IoT (M-IoT) will be the second dominant use case required for indoor 5G networks. Indoor M-IoT will complement outdoor M-IoT architectures. Indoor massive IoT will begin with migration of existing low bands (sub-1 GHz) to NR. These will primarily be outdoor high-power macro radios. Specific improvements in 5G standards will improve cell-edge performance over 4G, which will help outdoor-in coverage to extend. This enables M-IoT deployments with 4G technology today, with a path to even higher scalability after 5G migration. Low-band outside-in massive IoT will be complemented as needed by using the layered mid-band spectrum deployed indoors for MBB, or even with low-band indoor in extreme cases.
Advantages of Distributed Radio for Massive IoT
Enables easy selective deployment in limited areas Flexible capacity assignment between bands Ability to share common RAN capacity with outside low band coverage Figure - Massive IoT use cases Critical IoT use cases
Critical Realtime IoT is the last of the three main use case categories to be addressed. Although many improvements have been made in LTE standards to improve end-to-end latency to approx. 5-10 ms, the critical realtime requirement of 1 ms latency can only be achieved using innovations included in 5G standards. It will take some time for the required enhancements to both the radio access and core networks to reach full commercial availability.
Radio access networks for 5G will use new RF spectrum allocations that are much higher in frequency than the low- and medium-frequency bands optimal for mobile broadband and massive IoT. The addition of mmWave bands in the 20 – 60 GHz range is a critical step in the evolution of indoor 5G. Ultra-high bandwidth availble in mmWave spectrum enables massive throughput, while wider subcarrier spacing can improve critical realtime IoT latency. However, indoors, propagation will be limited to open areas with limited penetration through interior walls. These characteristics may constrain mmWave deployment to only those areas where the benefits are most required. Examples of such indoor spaces might include manufacturing assembly lines requiring extensive coordination of robotics and automated vehicles.
5G Core network advances include network slicing, enabling computation resources for critical realtime applications to be physically located at the edge of the network, reducing network transmission delays. Edge computing will be a key enabler.
Conclusion
Ericsson envisions indoor 5G networks of the future to be based on a deep layering of midband spectrum, complemented by outside-in low bands for M-IoT and indoor mmWave bubbles for ultra-high capacity and realtime critical IoT. Distributed Radio architectures are best suited to meet the challenges due to their low deployment cost, flexible capacity and close coordination between bands and with surrounding RAN deployments.
Network operators, enterprises and policy makers should consider the 5G use cases that will be needed in the future to ensure that infrastructure investments are not stranded. When modernizing existing in-building networks with 4G, build a foundation of coverage and capacity that will be easily expanded to include 5G capabilities in the future.