Microsoft Technology Licensing, LLC

Daehyeok Kim

Anuj Kalia

Ilias Marinos

Paramvir Bahl

Jitendra Dattatraya Padhye

Shachar Raindel

Anirudh Badam

Xenofon Foukas

Hongqiang Liu

Yibo Zhu

Tao Ji

Bozidar Radunovic

Ganesh Ananthanarayanan

Manikanta Kotaru

Wei Bai

Nikita Lazarev

During a first transmission time interval (TTI) of a vRAN, data traffic between a radio unit (RU) of a cellular network and a first vRAN instance of the vRAN is monitored. The first vRAN instance executes on a first server of the vRAN and the first vRAN instance is configured to perform PHY layer processing and L2 processing of the data traffic. Based on the data traffic between the RU of the cellular network and the first vRAN instance during the first TTI, a workload at the first vRAN instance during a second TTI is estimated.

Load estimation and balancing in virtualized radio access networks

A real-time radio intelligent controller (RIC) executes in parallel with one or more virtual radio access network functions to provide real-time analytics and control of the virtual radio access network functions. At least a first processor core is configured to execute a radio network virtual function. The radio network virtual function is configured with a codelet to output selected operational data to a first stream associated with a first stream ID and receive control information from a control stream associated with a second stream ID. At least a second processor core is configured to execute the real-time RIC isolated from the at least the first processor core. The real-time RIC includes one or more dynamically loaded programs configured to: access the first stream; perform processing on the operational data; and write commands for the radio network virtual function to the control stream.

Real-time radio intelligent controller

Aspects of the present disclosure relate to allocating workloads to vRANs via programmable switches at far-edge cloud datacenters. Traditionally, traffic allocation is handled by dedicated servers running load-balancing software. However, rerouting RAN traffic to such servers increases both energy and capital costs, degrades end-to-end performance, and requires additional physical space, all of which are undesirable or even infeasible for a RAN far-edge datacenter. Since switches are located in the path of data traffic, workflow policies can be designed to inspect packet headers of incoming traffic, evaluate real-time network information, determine available vRAN instances, and update the packet headers to steer the incoming traffic for processing. As network conditions change, the workflow policies enable the switch to dynamically redirect workloads to alternative vRANs for processing. As a result, RAN processing efficiency and fault tolerance are improved—even with changing network conditions and spikes in data traffic.

Switch-based workload distribution for virtualized RANs

Methods and systems for dynamically re-routing layer traffic between different servers with little user-visible disruption and without modifications to the vRAN software stack are provided. For instance, transformations on messages between the L2 and PHY, such as duplication and filtering, enable the system to maintain one or more low-overhead 'hot, inactive' PHY clones. A hot, inactive PHY clone may be a duplicate of an operational PHY, where the PHY clone is primed to process a PHY workload of the operational PHY (e.g., “hot”) but is not currently responsible for processing the PHY workload (e.g., low-overhead, inactive). In this way, a PHY workload may be automatically and seamlessly migrated to the hot PHY clone in response to planned downtime (e.g., scheduled maintenance, software upgrades) or unexpected events (e.g., server failures) within the strict transmission time intervals (TTIs) required for processing the PHY workload.

Creating elasticity and resiliency in virtualized RANs

Data traffic is communicated between a radio unit (RU) of a cellular network and a virtualized radio access network (vRAN) instance of a vRAN. In response to determining that the vRAN instance has failed to communicate a downlink fronthaul packet to the RU within a threshold timeout interval, a failure notification is sent to a PHY layer failure response function. The failure to communicate the downlink fronthaul packet to the RU within the threshold timeout interval is indicative of a failure of the vRAN instance.

Detection of failures in virtualized radio access networks

Techniques of packet level redundancy in distributed computing systems are disclosed herein. In one example, upon receiving an original packet to be transmitted from a source host to an application executing at a destination host, the source host generates a duplicated packet based on the received original packet. The source host can then encapsulate the original and duplicated packets with first and second outer headers having first and second header values, respectively, and transmitting the original and the duplicated packets from the source host to the destination host via a first network path and a second network path in the computer network, respectively. Then, the transmitted original and duplicated packets can be de-duplicated at the destination host before providing the de-duplicated original and duplicated packets to the application executing at the destination host.

Packet level redundancy in distributed computing systems

Methods and systems for dynamically re-routing layer traffic between different servers with little user-visible disruption and without modifications to the vRAN software stack are provided. This approach enables operators to initiate a PHY migration either on demand (e.g., during planned maintenances) or to set up automatic migration on unexpected events (e.g., server failures). It is recognized that PHY processing in cellular networks has no hard state that must be migrated. As a result, layer traffic such as the PHY-L2 traffic or L2-PHY traffic can be simply re-routed to a different server. This re-routing mechanism is realized by interposing one or more message controllers (e.g., middlebox) in a communication channel between the PHY and L2.

Dynamic re-routing and modification of layer traffic in virtualized RANs

Described are examples for providing a distributed fault-tolerant state store for a virtualized base station. In an aspect, a first server at a datacenter may perform physical layer processing for at least one virtualized base station. While performing the physical layer processing, the first server may generate inter-slot physical layer state data during a first slot. The inter-slot physical layer state data is to be used in a subsequent slot. The first server may periodically transmit the inter-slot physical layer state data to one or more other servers of the plurality of servers within the datacenter. One of the other servers may take over the physical layer processing for the at least one virtualized base station based on the inter-slot physical layer state data, for example, in response to a fault at the first server or a migration of the at least one virtualized base station.

Distributed fault-tolerant state store for virtualized radio access networks

Systems and methods are provided for offloading a task from a central processor in a radio access network (RAN) server to one or more heterogeneous accelerators. For example, a task associated with one or more operational partitions (or a service application) associated with processing data traffic in the RAN is dynamically allocated for offloading from the central processor based on workload status information. One or more accelerators are dynamically allocated for executing the task, where the accelerators may be heterogeneous and my not comprise pre-programming for executing the task. The disclosed technology further enables generating specific application programs for execution on the respective heterogeneous accelerators based on a single set of program instructions. The methods automatically generate the specific application programs by identifying common functional blocks for processing data traffic and mapping the functional blocks to the single set of program instructions to generate code native to the respective accelerators.

Generating abstractions for offloading tasks to heterogeneous accelerators

Described are examples for providing cell level migration of physical layer processing in a virtualized base station. A system for operating virtualized base stations includes a plurality of physical layer (PHY) servers within a datacenter and a media access control (MAC) server. Each respective PHY server includes: a memory storing instructions and at least one processor coupled to the memory. The at least one processor is configured to perform physical layer radio access network processing for a cell at the respective PHY server. The MAC server includes a memory storing instructions and at least one processor coupled to the memory. The at least one processor is configured to migrate the physical layer radio access network processing for the cell from a first server of the plurality of PHY servers to a second server of the plurality of PHY servers within the datacenter at an inter-slot boundary.

Migrating physical layer in virtualized radio access networks

Distributed storage systems, devices, and associated methods of data replication are disclosed herein. In one embodiment, a server in a distributed storage system is configured to write, with an RDMA enabled NIC, a block of data from a memory of the server to a memory at another server via an RDMA network. Upon completion of writing the block of data to the another server, the server can also send metadata representing a memory location and a data size of the written block of data in the memory of the another server via the RDMA network. The sent metadata is to be written into a memory location containing data representing a memory descriptor that is a part of a data structure representing a pre-posted work request configured to write a copy of the block of data from the another server to an additional server via the RDMA network.

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Pittsburgh, PA, United States of America

Daehyeok Kim