The choice of RAN split in 5G deployment depends on many factors and is not limited to just radio network deployment scenarios, intended supported services, existing infrastructure, or cost competitiveness. RRC along with PDCP-C will be part of CU-CP, and the SDAP/PDCP-U will be associated with CU-UP. Any fronthaul delays may reduce the benefits from shorter subframes and wider channel bandwidth, but offers greater advantage in cases of non-ideal transmission conditions and during mobility because the automatic repeat request (ARQ) is centralized in the CU. Editorial Report: Test and Measurement: Navigating operations, assurance and new spectrum Rohde & Schwarz White Paper: Emerging Trends in Wireless Infrastructure, Rohde & Schwarz White Paper: 5G Voice over New Radio. To meet these requirements, 5G topology introduced a new mindset of creating and defining a multi-split architecture. Using this split, the fronthaul bitrate will achieve extra overhead from scheduling control, synchronization and the Ethernet frame. The final part of this document provides an overview of how these various aspects related to the LLS are developing. 0000002710 00000 n
Most of the L1/L2 functions which need high processing power can be virtualized in this split and then enable efficient resource utilization and optimization from the SMO layer in O-RAN. Mobile Network Operators (MNOs) as well as industry-standards groups, such as the 3GPP, IEEE, Telecom Infra Project (TIP), and O-RAN, have been rethinking network architectures. View 3 excerpts, references background and methods. 5G brings higher throughput and extended cell edge coverage benefits as compared to LTE. It is best suited for small cell fem-to-cell like deployment as well as where heterogeneous backhaul and fronthaul with variable performance is available and the cost to cater for different small cells is needed. 0000004028 00000 n
There is a trade-off in terms of performance, complexity, flexibility, and transport demands that can allow an operator to decide what RAN decomposition(s) to deploy. 5G DRAN (Source: Intel Silicon Photonics Solutions), 3GPP Split Option 2 Fronthaul Rate Estimates, 3GPP Split Option 7 Fronthaul Rate Estimates, Click to share on Twitter (Opens in new window), Click to share on Facebook (Opens in new window). 0000022520 00000 n
The MAC-PHY layer split is being standardized by the Small Cell Forum (SCF) with the nFAPI (network FAPI) interface designed to enable Open RAN. The DU connects to RRHs that could be anywhere from a few meters to 10 km from the DU, and the BBU/RRH workloads are split accordingly. Such a model, with Control Plane User Plane Separation (CUPS) like design, would bring more flexibility. This became possible because of higher spectrum, flexible air interface, high order MIMO with smart beamforming, access agnostic and disaggregated RAN with flexible deployment options. Service providers should consider these tradeoffs and their specific use cases when selecting the RAN split option that will best meet their requirements for their 5G deployments. This study proposes the use of a packet-based fronthaul network and studies the joint impact of different packetization methods and RRH-BBU functional splits on the FH rate and latency. This paper evaluates, by mathematical and simulation methods, different splits with respect to network level energy and cost efficiency having in the mind the expected quality of service and derives a principle for fronthaul dimensioning based on the traffic profile. 0000004684 00000 n
IEEE INFOCOM 2019 - IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS). The article 'Exploring functional splits in 5G RAN: Tradeoffs and use cases' is available here. Mohamed Abdel Monem is an enthusiastic 5G Researcher and Instructor in Egypt and the Middle East and 0000052945 00000 n
2017 IEEE International Conference on Communications Workshops (ICC Workshops). If a bandwidth of 100 MHz using a sub-carrier spacing (SCS) of 60 kHz is assumed, then a 3-sector antenna using a single carrier with a 44 antenna arrangement would require around 34 Gbps fronthaul capacity across an option 7 split, while an 88 arrangement would require around 67 Gbps. 0000043330 00000 n
All physical processing is handled locally, and the MAC scheduler is centralized. 0000015266 00000 n
This work provides an overview of the various RAN functional split options and their relative trade-offs. Because of the increase in the scale of 5G, a more efficient fronthaul interface is needed. However, processing and memory requirements are increased in the O-RRU. Since 1982, RCR Wireless News has been providing wireless and mobile industry news, insights, and analysis to mobile and wireless industry professionals, decision makers, policy makers, analyst and investors. How much is fronthaul latency budget impacted by RAN virtualisation ? As industry bodies consider new network architectures, a key consideration is a functional split that separates layers between the BBU and the RRH. If we compare split 7.2x with Split 2, the fronthaul bitrate will achieve extra overhead from scheduling control, synchronization and the Ethernet frame. This work also provides an overview of the various industry activities that together form a toolbox enabling an operator to deploy the RAN functional split(s) of their choice. trailer
<<7820476C508A41298F8FBC36F5E333B3>]/Prev 490212>>
startxref
0
%%EOF
178 0 obj
<>stream
This will impact the network architecture as, for example, it can determine the placement of nodes and the distance between them. This site uses cookies to improve and personalize your experience and to display advertisements. A virtual network embedding (VNE) algorithm is proposed to flexibly select the appropriate functional split for each small cell, formulated as an integer linear programming (ILP) problem whose objective is to jointly minimize the inter-cell interference and the fronthaul bandwidth utilization. IEEE/OSA Journal of Optical Communications and Networking. Delivers only marginal multiplexing gains in the CU pool because most of the critical functions are in the DU which can be part of on-site or close-to-cell site deployment such as in a local data center. Shortly after LTE reached maturity, service providers started facing new challenges to meet customer demand for high capacity and always-on connectivity with quick set-up and transition time, spurred by diverse new applications and extremely high data usage by subscribers. Cookie information is stored in your browser and performs functions such as recognising you when you return to our website and helping our team to understand which sections of the website you find most interesting and useful. The HLS is progressing as a work item within 3GPP. Key constraint in this approach is high latency stringent requirement because of subframe-level timing interactions between part of PHY layer in CU and part of PHY layer in DUs. %PDF-1.6
%
0000092498 00000 n
As network architects work to meet the 5G challenges of increased traffic and data flows, a fundamental question is how much intelligence to put near the antenna versus at the DUs or CUs. Communication Engineering Frontier Knowledge Base. AT&T brings private 5G network, MEC to Fords new electric vehicle Chinese telcos add almost 44 million 5G subscribers in September, Revenue boost for automotive industry from cellular connectivity outweighs SEP licensing costs (Analyst Angle), Comcast, Charter continue rapid mobile growth, These are the elements required to deploy an IoT solution, Want to know the future of 5G and 6G? If you disable this cookie, we will not be able to save your preferences. Initially, the proposal to handle such requirements was in the form of Cloud-RAN with ultra-dense small cells. Split 7.2x is the O-RAN Alliance fronthaul specification between O-DU to O-RRU. By clicking accept or continuing to use the site, you agree to the terms outlined in our. The 5G RAN has a number of architecture options, such as how to split RAN functions, where to place those functions, and what transport is required to interconnect them. In this split option, an in-band protocol is necessary to support modulation, multi-antenna processing and PRB allocation due to the separation of the physical layer and the MAC. DL FH bitrate = (Peak rate+ signaling rate) *(BW/control signal BW) *(# of layers/# of layers in control signal) *(8/6), UL FH bitrate = (Peak rate+ signaling rate) *(BW/control signal BW) *(# of layers/# of layers in control signal) *(6/4), For a scenario using 100 MHz bandwidth, 8 layers and 256 QAM modulation the bitrate will be DL 5.6 Gbps and UL 7.1 Gbps. The 5G RAN decomposition allows for a wide range of 5G services requirements to be met by allowing for RAN functionality to be split into centralised and distributed locations. However, with eight possible functional split options in 3GPPs 5G-NR RAN2 specification, one of the standards bodies which oversees the development of mobile protocols, it was tough to meet the fronthaul requirements. 0000007583 00000 n
The result is published in NGMNs 6G Use Cases and Analysis White Paper released today. 0000053648 00000 n
There is no Low PHY/High PHY split; instead the full stack of the PHY layer and the RF are in the DU/RU. Great multiplexing gains on fronthaul link can be achieved because of centralized or common scheduler. The MAC, RLC and upper layers will be part of the central unit (CU). Features requirement for the RAN like DSS, NR-NR CA, NR-NR-DC, TDD-FDD mode and more. The answer depends on the use case and the choice of the functional split will determine the transport capacity requirement and associated latency specifications and performance. This split has been further optimized by the O-RAN Alliance into two variants: split 7.2a and split 7.2b. 2017 13th International Conference on Network and Service Management (CNSM). Rohde & Schwarz White Paper: 5G Evolution On the Path SureCall White Paper: As Data Demand Grows, Eventually Everyone Has to Editorial Webinar: 6G: What problems will the next generation of cellular Editorial Webinar: Open RAN in 2022: Enabling a Continuous Flow of Qualcomm Webinar: 5G mmWave today Insights on monetization and global Editorial Webinar: 5G Standalone: What does the move to cloud-native mean Editorial Webinar: The business case for 5G mmWave: Charting a path Telit to acquire Thales IoT unit for 25% of expanded, rebranded industrial IoT business, Sigfox back from the dead in South Africa after customers rally, investors emerge, Ferry company Stena Line deploys dual-band LoRa/LoRaWAN for cargo tracking, Honeywell invests in RapidSOS emergency response data platform, Buildings have to be programmable,? 38 0 obj
<>/Encrypt 8 0 R/Filter/FlateDecode/ID[<097E52E824AC76408D9FA48F9298BC65><2C5DD25C2F2EF4458190A6FA78BD22EA>]/Index[7 58]/Info 6 0 R/Length 137/Prev 204102/Root 9 0 R/Size 65/Type/XRef/W[1 3 1]>>stream
Supports multi-TRP, Joint Reception, multiple Carrier aggregation and similar features which need low latency. From a DU cost perspective, split 7.2x is more cost effective when compared to DUs supporting split 2 as more functions are shifted to O-RRU in split 7.2x which further enables more virtualization gains. 0000039518 00000 n
Ultimately, a flexible radio can address the service or operator requirements considering these trade-offs, potentially starting with a higher layer and a lower layer option. page where he walks his followers through a full understanding of the upcoming 5G technology covering A virtual network embedding (VNE) algorithm is proposed to flexibly select the appropriate functional split in order to mitigate the fronthaul requirements imposed by the Cloud-RAN architecture. 0000095064 00000 n
The nFAPI-like interface allows service providers to mix distributed and central units from different vendors to connect to any small cell radio unit (S-RU). I wrote a review of the book here and Sasha kindly made a video for our channel which is embedded below: Finally, RCR Wireless published an article looking at the 5G functional splits in detail, by Ankur Sharma, Associate Vice President, Product Management and Strategy, Radisys. That means how the RAN can be disaggregated into distributed components (DU) and centralized components (CU). The DU connects to RRHs that could be anywhere from a few meters to 10 km from the DU, and the BBU/RRH workloads are split accordingly. We are using cookies to give you the best experience on our website. *d00?$7H` 0
0000096332 00000 n
0000006635 00000 n
Optimal functional split selection and scheduling policies in 5G Radio Access Networks, Pacing the way toward 5G has lead researchers and industry in the direction of centralized processing known from Cloud-Radio Access Networks (C-RAN). 0000097273 00000 n
2016 IEEE International Conference on Communications (ICC). Variant 2: In addition to Variant 1, this split option comes with control and user split like in a CU-CP and CU-UP. Editorial Report: The business case for 5G mmWave: Charting a path Editorial Report: Private Networks in 2022: Why Private 5G Networks Matter. 0000094522 00000 n
Some additional factors to consider include: When talking about end-to-end network topology, we must consider that these split options will provide adequate gains if other network elements like transport, data center placement and connectivity, packet core, infrastructure programmability, automation, data collection and analytics, cloud native platform and others are considered as well. 0000008132 00000 n
0000094447 00000 n
hbbd```b``z"D%H 3lA$w6DN86
H2 This greatly reduces the amount of data transmitted across the interface. 0000095901 00000 n
60598 Frankfurt am Main, Germany, Phone: +49 69 907 49 98 0 0000006672 00000 n
%%EOF
0000095561 00000 n
He has his own professional Blog, Youtube channel, and Facebook technical Each of these describes how the centralised units and distributed units interrelate to one another, and what specific activities will be undertaken by each. Check your inbox or spam folder to confirm your subscription. Split 7.2x: Low PHY/High PHY split. Split 7.2x comes with fronthaul compression techniques like BFP IQ compression and de-compression to further reduce transport bandwidth. 5G is being deployed today as Unified Delivery Network (UDN), Fixed Wireless Access (FWA), Non-Public Network (NPN) / Public network integrated NPN (PNI-NPN) and many more topologies to address diverse use cases. endstream
endobj
startxref
0000094646 00000 n
The below figure illustrates a complete view (interface connectivity within RU/DU/CU) of O-RAN split 7.2x: 7.2a splits supporting RRU are much simpler and lower in cost as compared to 7.2b splits supporting O-RRU due to how much functionality has been pushed to the O-RRU or remains in the O-DU. The uplink performance is key to fully unlock the value of 5G. 0000043246 00000 n
It has two variants: 7.2a and 7.2b based on where precoding occurs. Many fronthaul connections use the Common Public Radio Interface (CPRI) connection protocol, which has been used mainly for point-to-point transport for macro base stations. Its most important advantages are centralized encryption/integrity and enhanced coordination of mobility and session transfer procedures. Latest news and information on 3G, 4G, 5G wireless and technologies in general. Split 6 enables multiplexing gains for different UE densities which results in a significantly decreased number of DUs. 0000039245 00000 n
In C-RAN research, a variety of different functional splits is presented by different names and focusing on different directions. This work uses as a reference architecture the 3GPP LTE stack, and argues about the functional split applicability in contemporary networks, and evaluates Layer 2 functional splits, that can be used for the convergence of multiple heterogeneous wireless technologies in an all-in-one unit. This option is like 3GPP Release 12 based LTE dual connectivity (option 3C) which can handle multiple flows to various access nodes to enable multi-connectivity scenarios. 7 0 obj
<>
endobj
This website uses cookies so that we can provide you with the best user experience possible. The Open RAN Alliance as well as the Small Cell Forum (SCF) evolved their specifications to support 5G functional splits with two additional versions: Not all split options are considered ideal for initial 5G deployments. Ultimately, a flexible radio can address the service or operator requirements considering these trade-offs, potentially starting with a higher layer and a lower layer option. 0000034003 00000 n
0000053561 00000 n
0000093380 00000 n
0000005592 00000 n
This means that every time you visit this website you will need to enable or disable cookies again. A new cooperation scheme to manage the adaptive flexible functional split in 5G networks conditioned to the resource availability in the optical access network is proposed and results show that the proposed software defined converged approach to wavelength and bandwidth management guarantees the optimal allocation of optical resources. Click on one of the links below to read the article in full below: Orange launches 1st dedicated OpenRAN lab in France, Benetel joins SONIC program to accelerate UK 5G roll-out, https://www.5gtechnologyworld.com/functional-splits-the-foundation-of-an-open-5g-ran/, https://issuu.com/wtwhmedia/docs/5g_handbook. Fronthaul Slicing Architecture (FSA) is designed and implemented, which to the best of the knowledge, is the first slicing architecture for the fronthaul network and enables multipoint-to-multipoint routing as well as packet prioritization to provide multiplexing gains in the fr onthaul and the C-RAN, making the system more scalable. That means how the RAN can be disaggregated into distributed components (DU) and centralized components (CU). Radio resource control and packet data convergence control are split from the Layer 2 radio link control (RLC). RLC, medium access control (MAC), and high physical layer will be part of the DU, and the low physical layer along with the RF are in the DU. According to the results, fixed scheduling behaves alike the global optimum in heterogeneous RAN scenarios, and it is usually better to optimize the split degree for fixed scheduling setups, than deciding a scheduling policy for a particular split configuration. Also in the White paper Exploring 5G Fronthaul Network Architecture Intelligence Splits and Connectivity by Intel, theres a good example for 5G DRAN deployment as below: This 5G DRAN deployment example shows an architecture using either an option 2 or option 7 extensible Radio Access Network (xRAN) split for sub-6 GHz, where the DU can be at or near the antenna site. both engineers and undergraduates. 0000002582 00000 n
99 80
2019 IEEE 90th Vehicular Technology Conference (VTC2019-Fall). The basic question is how much compute to put at the BBU as opposed to at the RRH. 0000052171 00000 n
Powering the Future of Wireless Connectivity, Exploring functional splits in 5G RAN: Tradeoffs and use cases (Reader Forum). We use cookies to ensure that we give you the best experience on our website. 0000007070 00000 n
An optimization model is formulated, Apt-RAN, that optimizes the energy consumption of the CU pool and the number of handovers, considering different functional splits, and a lightweight polynomial time heuristic algorithm is proposed. This 5G DRAN deployment example shows an architecture using either an option 2 or option 7 extensible Radio Access Network (xRAN) split for sub-6 GHz, where the DU can be at or near the antenna site. In this work, a discussion on the challenges and open issues of joint slicing and functional splitting is posed, taking into account the additional complexity resulted from instantiating multiple slices per DU, each one with a different functional split. It is embedded below: The next one is slightly detailed video from the book "5G Radio Access Network Architecture: The Dark Side of 5G" by Sasha Sirotkin (Editor). The Status of 5G Standalone (5G SA) Networks - Mar Initiative to Remove Non-inclusive terms from 3GPP India government wants home-grown 5G; BSNL and MTNL will emerge as healthy, Three Essentials When It Comes To Investing, Haptics and Telepresence with 5G Connectivity, Uruguay is a Land of Opportunity and Connectivity, Germany Launches 6G-Access, Network of Networks, Automation and Simplification (6G-ANNA) Project, Diameter Routing Agents (Why you need them, and how to build them) Part 1, New Report on Enterprise Wi-Fi: No, 5G is not enough, Google Task Mate App Referral Code | Task Mata APP to earn money, Three UK's 5G C-RAN Infrastructure in Birmingham, UK, Observations on Canadas 3800 MHz Frequency Spectrum Auction, Episode 31: Analog Modulation and Over-the-Air Aggregation, I've Been Bigly And Bad - The Trump Musical, Indoor motorcycle training in Milton Keynes, A 5G Use case! 0000091896 00000 n
0000092645 00000 n
end-to-end research and news. Choice of different options from a fully distributed to a fully centralized RAN architecture can address different requirements, offering the associated benefits (such as edge computing, high throughput at high mobility or centralized processing and simplified distributed coverage), within constraints (such as cost or transport requirements). 0000029886 00000 n
99 0 obj
<>
endobj
xref
0000095139 00000 n
This split enables complete separation of the RF from the Physical layer to maximum virtualization gains. 0000006186 00000 n
0000007296 00000 n
I have been meaning to write a post on RAN functional splits and even make a video. Therefore, operators, technology suppliers and academic advisors in NGMN joined forces and contributed their views on which 6G use cases they predict will emerge in the future decade. Cloud radio access network (CRAN) enables advanced coordination algorithms to be employed in dense small cell networks by centralizing baseband signal processing at powerful computing infrastructures, called centralized unit (CU) pools. Todays 5G networks are meant to support various applications with diverse requirements such as latency, high data rates and real-time support for random traffic demands. This work investigates whether a fine-grained functional split architecture could benefit to the RAN evolution, and how it impacts on the converged optical-wireless access networks, and proposes a mixed-integer linear programming model (MILP) considering the PP selection, routing, wavelength and bandwidth assignment. 0000000016 00000 n
0000053207 00000 n
Note that the option 2 split fronthaul requirement capacity is much less, requiring a lower-capacity optical link. This paper proposes an optimization problem that maximizes the centralization of the C-RAN system by operating more number of DUs on split Option-7 by changing the channel bandwidth of the DUs. 0000048436 00000 n
IEEE Transactions on Network and Service Management. Similar to LLS-HLS in split 7.2x, split 6 also has very strict delay requirements as the HARQ and other time critical procedures are centralized in the CU-pool. 0000014543 00000 n
Thank you for joining our live NGMN Press and Industry Briefing on March 1, 2022 from 1:30 -2:30 pm CET at MWC stand 3M31. hb```f`` tA,Sx$. Rakuten Communications Platform partners with Airspan on Open RAN network blueprint. 64 0 obj
<>stream
0000091426 00000 n
After extensive discussions, 3GPP defined two 5G-NR split architectures in addition to the traditional monolithic one: Further evolution was needed to support these two architectures to reduce complexity in the remote radio unit (RRU), to bring more intelligence to the local RAN, to increase cost competitiveness and resiliency, and to support disaggregated spectrum and efficient transport utilization. The functional split options can broadly be classified as either a high layer split (HLS) or a low layer split (LLS). Many industry groups including, 3GPP, eCPRI, xRAN, TIP, TTA, SCF, IEEE 1914, IEEE 802.1CM, are working on parts of the puzzle and specifications are already available or soon to be available from many of these groups. This paper investigates new functional split architectures between RRH and BBU, to reduce the transmission throughput betweenRRHs and BBUs, and proposes to move part of physical layer functions of the BBU to the RRH. Split 2 brings SDAP/PDCP with RRC into the centralized unit while all L2/L1 functions will be part of the local or centralized DU. 0000013880 00000 n
The below architectures show distributed radio access network (DRAN) examples where the BBU is either fully integrated at the tower or integrated at a distribution site at or near the tower, and centralized radio access network (CRAN) examples showing partially centralized RAN and fully centralized vRAN. Joint processing on multiple access node is possible (Transmit/receive at same time on different nodes). This split transfers PDCP/SDAP PDUs in the DL and receives RLC SDUs in the UL direction. Verticals use cases need sufficient uplink throughput or cell capacity and low enough latency, when 5G Time-Division Duplex (TDD) bands are used to successfully realize their industrial use cases. 0000007680 00000 n
Specific QoS requirement for offered services (e.g., low latency, high throughput), Network densification, traffic profile, bandwidth demand, available spectrum with RF features like MIMO, E2E transport availability networks with different performance levels, from ideal to non-ideal. 0000007429 00000 n
Also in the White paper Exploring 5G Fronthaul Network Architecture Intelligence Splits and Connectivity by Intel, theres a good example for 5G DRAN deployment as below: 2017 IEEE Conference on Network Function Virtualization and Software Defined Networks (NFV-SDN). 0000053321 00000 n
This split brings centralized PDCP entity (user plane) which can be separated from RRC/RRM (control plane), hence it is highly latency tolerant. 0000091666 00000 n
The functional split determines how many base station functions to leave locally, close to the user, with the benefit of relaxing fronthaul network bitrate and delay requirements, and how many functions to centralize. An overview of the 3GPP activities related to the HLS is provided here. While these approaches helped alleviated some of the issues, they also increased service providers CAPEX and OPEX and significantly reduced profitability. Split 8: PHY-RF split. DL FH bitrate = Sub Carrier*# of Symbol*# of layers*IQ size*2*1000 +MAC info, UL FH bitrate = Sub Carrier*# of Symbol*# of layers*IQ size*2*1000 +MAC info, For the same scenario as above using 100 MHz bandwidth and 32 antenna ports the DL bitrate will be 9.8 Gbps and the UL 15.2 Gbps. Semantic Scholar is a free, AI-powered research tool for scientific literature, based at the Allen Institute for AI. 0000095486 00000 n
0000024705 00000 n
says Cisco?s smart building lead, View to install smart windows at Skanska office project in Seattle, BAI Communications to acquire ZenFi Networks, Wi-Fi 6E: A spectrum update, not just a technology update, Tupl CEO: The role of automation is paramount. 5G Radio Access Network Architecture: The Dark Side of 5G by Sasha Sirotkin (Editor), The Status of 5G Standalone (5G SA) Networks - March 2021, Initiative to Remove Non-inclusive terms from 3GPP Specifications, Everything you need to know about 5G Security, Open RAN Explanation, Videos, White papers and Other Resources.