The results show that state-of-the-art techniques fail at maximizing the centralization degree and that the achievable C-RAN centralization highly depends on the underlying topology structure. 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. 60598 Frankfurt am Main, Germany, Phone: +49 69 907 49 98 0 To address some of these challenges, service providers began spending on new hardware and software for Radio Access Network (RAN) upgrades, spectrum refarming, and co-existence of licensed-unlicensed multi-mode deployments. 0000000016 00000 n
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If precoding and resource element mapper are part of the O-DU and the O-RRU handles beamforming onwards then it is 7.2a split. The first is this basic introductory video from Parallel Wirelesswhere they explain why you need RAN splits providing examples of various functional splits for 4G and 5G mobile networks. 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. Such a model, with Control Plane User Plane Separation (CUPS) like design, would bring more flexibility. %%EOF
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. (Part 1), Option 2 a high-level centralized Unit (CU) and distributed Unit (DU) split which is primarily a separated control and user plane, Option 7 (or 7.2) a low-level split for ultra-reliable low-latency communication (URLLC) and near-edge deployment, O-RAN Alliance defined the low-level split (option 7.2x). Note that the option 2 split fronthaul requirement capacity is much less, requiring a lower-capacity optical link. This split enables complete separation of the RF from the Physical layer to maximum virtualization gains. 0000091426 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. 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. This split is an already standardized PDCP-RLC split like in LTE dual connectivity. NGMN Alliance e.V. Disaggregated hardware and software would enable more efficient scaling, allowing service providers to customize their networks to align with their own demand needs and available infrastructure. This split brings centralized PDCP entity (user plane) which can be separated from RRC/RRM (control plane), hence it is highly latency tolerant. There are a number of ways in which modern decentralised fronthaul networks can be arranged, with the 3GPP defining a series of different functional split options that network operators can implement. 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). Layers from MAC and above will benefit from enhanced processing in the CU-pool, hence a virtualized platform is limited to L2/L3 only, unlike in option 7.2x where High PHY can be part of virtualized platform. 2016 IEEE 83rd Vehicular Technology Conference (VTC Spring). 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. The identification of 6G use cases is key to predicting major trends in future usage scenarios and will help to steer the needs and requirements for future generational change. 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. 0000096823 00000 n
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RED Smartphone with LEIA Holographic Display Tech, LTE for drone flight management and situational awareness, LTE-Advanced taps into unlicensed spectrum with Licensed Assisted Access. We use cookies to ensure that we give you the best experience on our website. 0000092268 00000 n
Requires an in-band protocol needed for modulation, multi-antenna processing and PRB allocation. 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. This paper presents the design of an adaptive RAN that can switch between two different centralization options at runtime, and provides design objectives and challenges, as well as measurement results from a working implementation. page where he walks his followers through a full understanding of the upcoming 5G technology covering What does Functional Split mean? 0000043246 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. 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. hbbd```b``z"D%H 3lA$w6DN86
H2 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. Rakuten Communications Platform partners with Airspan on Open RAN network blueprint. Its most important advantages are centralized encryption/integrity and enhanced coordination of mobility and session transfer procedures. 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. Requires a re-sequencing buffer in both DU and CU so that packets arrive in the correct sequence. It has two variants: 7.2a and 7.2b based on where precoding occurs. 0000012453 00000 n
IEEE/OSA Journal of Optical Communications and Networking. %PDF-1.5
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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. 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. 0000039245 00000 n
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Radio resource control and packet data convergence control are split from the Layer 2 radio link control (RLC). 0000053321 00000 n
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IEEE Transactions on Network and Service Management. 0000095561 00000 n
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. 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. 0000003886 00000 n
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5G brings higher throughput and extended cell edge coverage benefits as compared to LTE. The uplink performance is key to fully unlock the value of 5G. Split 2 can be deployed in two variants: Split 6: MAC/PHY layer split. Variant 1: RRC, service data adaptation protocol (SDAP) & PDCP in the same central unit as one entity; no control and user split. 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. 0000013880 00000 n
For 5G use cases, an ideal one-way latency is required and, in the worst case, near ideal in the MAC/PHY split. 0000002710 00000 n
Check your inbox or spam folder to confirm your subscription. 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. Fronthaul interface needs to meet certain QoS to ensure priority for time critical data. 2017 IEEE International Conference on Communications Workshops (ICC Workshops). For the LLS, the story is less mature, but still making significant progress. 0000048436 00000 n
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He has his own professional Blog, Youtube channel, and Facebook technical 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. However, processing and memory requirements are increased in the O-RRU. Centralized scheduling enables 5G enhanced feature support like multi-TRP, low-high band CA/DC, but it comes with a requirement of low latency relation between FEC and MAC as they are separated in this split and it comes with higher scheduling control overhead. Because of the control and user split, deployment is mainly focused on non-real-time applications running in the CU when transport requirements like latency and bandwidth are relaxed. 0000020044 00000 n
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Powering the Future of Wireless Connectivity, Exploring functional splits in 5G RAN: Tradeoffs and use cases (Reader Forum). Impact of Network Densification on Joint Slicing and Functional Splitting in 5G, Apt-RAN: A Flexible Split-Based 5G RAN to Minimize Energy Consumption and Handovers, An adaptive functional split in 5G networks, CU placement over a reconfigurable wireless fronthaul in 5G networks with functional splits, FSA: fronthaul slicing architecture for 5G using dataplane programmable switches, Minimizing Delay in NFV 5G Networks by Means of Flexible Split Selection and Scheduling, Traffic-Aware Dynamic Functional Split for 5G Cloud Radio Access Networks.