Frequently Asked Questions

Why was xRAN.org founded?
xRAN.org was formed by mobile carriers to promote a software-based, extensible Radio Access Network (xRAN) and to standardize critical elements of the xRAN architecture. xRAN.org members are dedicated to developing and standardizing an open alternative to the traditionally closed, hardware-based RAN architecture.

When was xRAN.org founded?
The initial member began working together in early 2016 and xRAN.org was formally launched in October 2016.

Why would I join xRAN.org?
Members have an opportunity to shape the future of mobile networking by promoting the development and commercialization of the next generation xRAN architecture. Membership also includes benefits such as early access to emerging reference designs, testing environments, and early adopter use cases.

Where can I find more information about xRAN.org?
http://www.xran.org

What traditional limitations does the xRAN architecture solve?
Current RAN architectures result in sub-optimal use of scarce spectrum and radio resources as well as make it hard for operators to program them quickly to meet emerging customer needs. Amid exploding demand for bandwidth and intense demands from new services, carriers need an alternative approach to tackle the escalating capital and operational costs of the existing design as well as make the network more agile to deploy new services.

What is different about the xRAN architecture?
xRAN fundamentally advances the RAN architecture in three areas – 1. Decouples the RAN control plane from the user plane, 2. Builds a modular eNB software stack that operates on common-off-the-shelf (COTS) hardware and 3. Publishes open north and southbound interfaces to the industry.

  • Decouple Control and User Planes: This migration of control, formerly tightly bound to RAN hardware devices, into accessible computing devices allows the underlying RAN to be more efficiently orchestrated as a logical pool of capacity. eNB software is decoupled from vendor specific hardware, inspiring innovation in both software and hardware cooperatively, but independently.
  • Modular, software-based eNB stack: The xRAN approach is well aligned with carrier Network Function Virtualization (NFV) initiatives, and provides high-performance, fine-grained traffic control, interference management and radio resource control on standard x86 platforms and across multi-vendor radio access interfaces.
  • Standardize North and Southbound Interfaces: Standard, open interfaces with multiple vendor support and proven interoperability. The xRAN.org and its members will drive adoption of these interfaces through standards processes, socialize the xRAN architecture and provide needed support.

What are the benefits of the xRAN architecture?
The xRAN architecture transforms today’s static, highly proprietary RAN infrastructure into an extensible, software-based service delivery platform capable of rapidly responding to changing user, application and business needs.

  • Decoupling control plane from user plane gives carrier’s unprecedented real-time programmability and control in their RAN infrastructure, which readily supports next generation mobile applications and business services.
  • A modular, software-based eNB stack approach enables flexible placement of eNB functions and hybrid split-control plane with a scheduler to handle variable front-haul latency and programmable control.
  • Standardized southbound interfaces enable multi-vendor implementations and northbound interfaces enable end-to-end network slicing to optimize user QoE. xRAN interfaces are well aligned with carrier edge cloud initiatives, allowing dynamic orchestration of compute and storage resources together with the mobile network.
  • Reduces capital expenses of growing RAN capacity and reduces the cost of operating the RAN through increased automation and reduced manual provisioning and per-box configuration.

Does xRAN.org specify new RAN protocols?
The interface between the xRAN controller and the eNBs facilitates low latency exchange of messages concerning resource utilization, user admission/handover, bearer establishment and more. xRAN.org specifies a protocol for this exchange of information between the programmable controller and the eNBs forwarding data. There is no additional RAN protocol, involved.

Has xRAN.org published a hardware reference platform?
xRAN.org will publish reference hardware platforms that will support the software stack and interfaces that xRAN produces.

What HW platforms are expected by the xRAN architecture?
Understanding that not all RAN functions (e.g. low level baseband processing functions) will operate most efficiently on fully COTS based GPP HW (ARM, x86) today, xRAN.org will work closely with COTS HW providers to improve efficiency for wireless applications. At the same time, we will work to optimize the abstraction of tasks and functions that require SPP HW.

Does xRAN.org specify open interface and provide open source code?
Initially, xRAN.org will publish reference implementations, not open source code, with the goal of demonstrating the benefits and feasibility of the xRAN architecture. Longer term, xRAN.org plans to promote its vision of an open, flexible and programmable xRAN architecture by both specifying open interfaces and providing open source frameworks.

Does xRAN.org have a test environment/lab?
xRAN.org is developing a test environment implementation guide. Carriers will build and manage their own test environments, but member will share test plans and findings.

Are there production deployments of the xRAN architecture?
Currently (October 2016), No. However, xRAN.org, hosted by DT, delivered a Multi-Vendor Reference Implementation Demonstration at NGMN Industry Conference & Exhibition on October 12th in Frankfurt.

How does the xRAN architecture relate to carrier Network Function Virtualization (NFV) initiatives?
Like most NFV initiatives, the xRAN architecture is designed as software that operates on Common Off-the-Shelf (COTS) hardware, reducing both CAPEX and OPEX costs.

How does xRAN.org work with 3GPP and other standards bodies?
The xRAN architecture is complementary to 3GPP and other standards bodies and hopes to provide a blueprint that these standards bodies can use for architecting the future RAN as the industry moves towards 5G. Using the programmable controller, the xRAN architecture, xRAN.org will work with 3GPP and other standards bodies in specifying standards that enable operators to make efficient radio resource management decisions such as:

  • Resource scheduling for the base stations,
  • User and traffic load-balancing across base stations,
  • Inter-cell interference management across the network, and
  • Power and beamforming configuration on the frequency resource chunks deployed on the base stations.

These decisions are crucial in the performance of next-generation 5G radio access technologies using, for example, Massive MIMO or Small-cell HetNets.
In addition to support of 3GPP standards, the xRAN architecture, with programmable resource allocation and flexible front-haul latency management, is complementary to mobile edge computing functionalities like content caching, which play a significant role in reducing the latency in 5G systems. With edge computing efforts such as CORD; xRAN would be realized on top of the CORD compute platform.