Microsoft Technology Licensing, LLC

Anuj Kalia

Daehyeok Kim

Paramvir Bahl

Ilias Marinos

Sanjeev Mehrotra

Manikanta Kotaru

Xenofon Foukas

Tao Ji

Yu Yan

Nikita Lazarev

Atul Bansal

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

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

A method for utilizing computing resources in a vRAN is described. A predicted resource load is determined for data traffic processing of wireless communication channels served by the vRAN using a trained neural network model. The data traffic processing comprises at least one of PHY data processing or MAC processing for a 5G RAN. Computing resources are allocated for the data traffic processing based on the predicted resource load. Wireless parameter limits are determined for the wireless communication channels that constrain utilization of the allocated computing resources using the trained neural network model, including setting one or more of a maximum number of radio resource units per timeslot or a maximum MCS index for the wireless parameter limits. The data traffic processing is performed using the wireless parameter limits to reduce load spikes that cause a violation of real-time deadlines for the data traffic processing.

Wireless parameter limits for predicted vRAN resource loads

Techniques are disclosed for dynamically adjusting associations between radio units (RUs) and a virtualized radio access network (vRAN) by a virtual translational layer running in a controller of the vRAN. Each of the RUs have a number of antennas and are configured to service a cell of a cellular communications network. Based on performance metrics, the virtual translational layer maps the RUs to a virtualized cell of the cellular communications network, the virtualized cell including a mapped selection of the RUs.

Virtualized cells with multiple antennas in a virtual Radio Access Network

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

Described are examples for deploying workloads in a cloud-computing environment. In an aspect, based on a desired number of workloads of a process to be executed in a cloud-computing environment and based on one or more failure probabilities, an actual number of workloads of the process to execute in the cloud-computing environment to provide a level of service can be determined and deployed. In another aspect, a standby workload can be executed as a second instance of the process without at least a portion of the separate configuration used by the multiple workloads, and based on detecting termination of one of multiple workloads, the standby workload can be configured to execute based on the separate configuration of the separate instance of the process corresponding to the one of the multiple workloads.

Techniques for deploying workloads on nodes in a cloud-computing environment

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.

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Newcastle, WA, United States of America

Anuj Kalia