BACKGROUND

Technical Field

The disclosed method and apparatus relate to communication networks and more particularly to methods and apparatus for real time monitoring of communication parameters in packet-based wireless communications networks to maintain quality of service and more efficiently use network resources.

Background

The wireless industry has experienced tremendous growth in recent years. Wireless technology is rapidly improving, and faster and more numerous broadband communication networks have been installed around the globe. These networks have now become key components of a worldwide communication system that connects people and businesses at speeds and on a scale unimaginable just a couple of decades ago. The rapid growth of wireless communication is a result of increasing demand for more bandwidth and services. This rapid growth is in many ways supported by standards. For example, 4G LTE has been widely deployed over the past years, and the next generation system, and 5G NR (New Radio) is now being deployed. In these wireless systems, multiple mobile devices are served voice services, data services, and many other services over wireless connections so they may remain mobile while still connected.

Wireless networks have a wide range of applications and uses. Enterprises particularly have a great interest in implementing wireless networks at their enterprise location, and digital solutions more generally, to improve efficiency and reduce costs. Enterprises benefit from optimizing their computing, storage and networking infrastructure, and improving performance of the business applications within their business location, which increases business efficiencies and reduces cost.

FIG.1is an illustration of a basic configuration for a communication network, such as a “4G LTE” (fourth generation Long-Term Evolution) or “5G NR” (fifth generation New Radio) network. Through this network configuration, user equipment (UE)101aand101bcan connect to External Packet Data Networks (PDNs)103and access any of a variety of services such as the Internet, Application Servers, Data Services, Voice Services, and others.

The UEs101aand101bconnect wirelessly over respective communication links105aand105bto a Radio Access Network (RAN)107that includes a base station/access point (BS/AP)109. One of the advantages of such networks is their ability to provide communications to and from multiple wireless devices and provide these wireless devices with access to a large number of other devices and services even though the devices may be mobile and moving from location to location.

UE

As used herein, the term “UE’ refers to a wide range of user devices having wireless connectivity, such as a cellular mobile phone, an Internet of Things (IOT) device, virtual reality goggles, robotic devices, autonomous driving machines, smart barcode scanners, and communications equipment including for example cell phones, desktop computers, laptop computers, tablets and other types of personal communications devices. In some cases, the UEs may be mobile; in other cases, they may be installed at a fixed location. For example, a factory sensor may be installed at a fixed location from which it can remotely monitor an assembly line or a robotic arm's movement.

BS/AP

The term ‘BS/AP” is used broadly herein to include base stations and access points, including at least an evolved NodeB (eNB) of an LTE network or gNodeB of a 5G network, a cellular base station (BS), a Citizens Broadband Radio Service Device (CBSD) (which may be an LTE or 5G device), a Wi-Fi access node, a Local Area Network (LAN) access point, a Wide Area Network (WAN) access point, and should also be understood to include other network receiving hubs that provide access to a network of a plurality of wireless transceivers within range of the BS/AP. Typically, the BS/APs are used as transceiver hubs, whereas the UEs are used for point-to-point communication and are not used as hubs. Therefore, the BS/APs transmit at a relatively higher power than the UEs.

Core Network

The RAN107connects the UEs101with the Core Network111, which has many functions. One function of the Core Network111is to provide control of wireless signaling between the UEs101and the RAN107, and another function is to provide access to other devices and services either within its network, or on other networks such as the External PDNs103. Particularly, in cellular networks and in private networks, the BS/AP109can receive wireless signals from, and send wireless signals to, the UEs101. The RAN107is coupled to the core network111; therefore, the RAN107and the Core Network111provide a system that allows information to flow between a UE in the cellular or private network and other networks, such as the Public Switched Telephone Network (PSTN) or the Internet. Wireless data transmission between a UE101and the BS/AP109occurs on an assigned channel, such as a specific frequency. Data transmission between the BS/AP109and the Core Network111utilizes any appropriate communication means, such as wireless, cable, and fiber optic.

4G and 5G Architectures

4G/LTE and/or 5G wireless communication networks; that is, communication networks that are constructed according to the specifications of Standard Development Organizations (SDOs) such as 3GPP, are well-documented. The basic components of these communication networks are well-known, and need not be discussed in detail, but are discussed briefly below. Much additional information is available in the current SDO specifications, such as 3GPP specifications TS 21.905, TS 22.852, TS 23.002, TS 23.203, TS 23.501, TS 36.300.

FIG.2is a block diagram showing one architecture of an LTE (4G) wireless communication system200. The 4G network has a flat, all-IP architecture with a separation of control plane and user plane traffic. Acronyms are shown in the network blocks.

FIG.3is a block diagram of a 4G architecture300in which bearers are illustrated by their letter symbols and lines connecting components.FIG.4is a block diagram of a 4G architecture400in which the bearers are illustrated by name type and by paths between components blocks. In LTE and 5G communication systems, a bearer is an information transmission path that has defined capacity, delay and bit error rate, and possibly other characteristics. Depending upon the configuration of the communication system as implemented, a number of bearers will be defined across different blocks of the system. As will be apparent to one skilled in the art, the bearers available in any particular network architecture may differ.

FIG.5is a block diagram of a 5G wireless communication network300. In this 5G architecture, a Core Network is referenced as 5GC (5G Core). InFIG.3, acronyms are shown in the network blocks.

CBRS Networks

One type of wireless network that recently became available for general use by enterprise locations is a Citizen's Broadband Radio Service (CBRS) network, which utilizes the CBRS radio band of 3550-3700 MHz, nominally divided into fifteen channels of 10 MHz each. Particularly, the US Federal Government recently approved use of the CBRS band of the frequency spectrum and finalized rules (Rule96) that allow general access to the CBRS band. The CBRS rules set forth detailed requirements for the devices that operate in a CBRS network and how they communicate. CBRS supports both LTE and 5G devices. Base stations (BS/APs) within a CBRS network are termed “CBSDs”, and UEs are termed End User Devices (EUDs). CBSDs are fixed Stations, or networks of such stations, that operate on a Priority Access or General Authorized Access basis in the Citizens Broadband Radio Service consistent with Title 47 CFR Part 96 of the United States Code of Federal Regulations (CFR).

Network Performance and Service

Communication networks such as 4G LTE or 5G NR networks deliver connectivity services for different mobile devices and different applications running over the network such as voice, video, real time control and web browsing. Usually these applications have a desired quality of service. For example, in enterprise networks with private 4G LTE or 5G NR systems, different applications require different levels of service in accordance with the needs of the application, and/or service level agreements (SLAs). Typically, these SLAs are translated to maximum bounds on specific Key Performance Indices (KPIs) such as packet error rate, packet delay and packet variation.

Creating end-to-end data paths (e.g. network slices) in 4G LTE and 5G NR networks is one way to provide appropriate Key Performance Indices (KPIs) for different applications. These end-to-end data paths may be designed to provide end-to-end QoS guarantees related to latency, packet delay variation and packet loss. In the 4G standards some end-to-end data paths are bearers, in 5G they may be network slices. For each end-to-end data path, the communication network needs to provide a way to monitor these KPIs to ensure the SLA requirements are met; i.e., to monitor the actual KPI and determine if it is within the desired range of KPIs for that data path.

Ideally these KPIs would be measured at the application server (e.g., which typically resides on the Internet) and client (e.g., which typically resides on the mobile device). However, these type of measurements at the server and client are typically not available and/or not done. It would be useful if these measurements could be made from communication network nodes between the server and client, which are more accessible. It would also be useful if these measurements could be made in near real-time, such as for applications running over the TCP/IP protocol.

SUMMARY

A method and apparatus are disclosed for monitoring network performance, which can be done in near real-time for applications running over the TCP/IP protocol, by making measurements at an intermediate node in the network. Although the following description is focused primarily on 4G LTE and 5G NR networks, the solution is useful for any communication network that connects a client and application server, or for any application running over TCP/IP protocol.

Various embodiments of a system for creating and measuring operational parameters in a packetized communications network are disclosed.

A method is disclosed for measuring end-to-end qualities of a packet-based communication session between a data sender (DS) and a data receiver (DR) at an intermediate node connected between the DS and DR of the communication network. One method comprises the steps of setting up a packet-based communication session between the DS and the DR to define a session packet structure, utilizing the session packet structure to generate session packets in the DS and the DR, and communicating the session packets through the intermediate node to the DR and DS. The packet stream received at the intermediate node includes a plurality of packets that include session packets and other, non-session packets. The session packets are identified from the plurality of packets in the packet stream, and data is selected and stored from the identified session packets. The stored data is processed to measure end-to-end communication qualities of the communication system, including at least one of latency, packet delay variation, and packet loss rate. In some embodiments, the packet-based communication session is a TCP/IP session.

A method is disclosed for measuring latency at an intermediate node of a packet-based wireless communication network during a timestamp-enabled communication session in which a plurality of packets are communicated between a data sender (DS) and a data receiver (DR). The timestamp-enabled session packets include a Timestamp value (TSval) and a Timestamp echo reply (TSecr) value. The latency measurement method includes receiving a first packet sent from the DS having a TSval=S_i, measuring a timestamp of arrival (t1) of the packet at the intermediate node, and sending the first packet to the DR. A reply packet is received at the intermediate node from the DR having a TSecr=S_i, and a timestamp of arrival (t2) of the packet is measured at the intermediate node. Responsive to t1and t2, a forward RTT value is calculated. The intermediate node receives a first return packet sent from the DR having a TSval=R_i, a timestamp of arrival (t3) of the packet at the intermediate node is measured, and the first return packet is sent to the DS. A return reply packet is received from the DR having a TSecr=R_i, and a timestamp of arrival (t4) of the packet is measured at the intermediate node. Responsive to t3and t4, a reverse RTT value is calculated. The forward and reverse RTT values are then processed to provide an overall RTT value. In some embodiments, the packet-based communication session is a TCP/IP session, the DS comprises a UE. and the DR comprises a server.

A method is disclosed for measuring packet delay variation (PDV) at an intermediate node of a packet-based wireless communication network during a timestamp-enabled communication session in which a plurality of packets are communicated between a data sender (DS) and a data receiver (DR). The session packets include a Timestamp value (TSval) and a Timestamp echo reply (TSecr) value. The PDV measurement method includes the steps of receiving, at the intermediate node, a first packet sent from the DS having a TSval=S_i, and measuring a timestamp of arrival (t1) of the packet. The intermediate node receives a second packet sent from the DS from the same session and having the same TSval=S_i. The timestamp of arrival (t2) of the second packet is measured at the intermediate node. The inter-packet arrival time between t_1and t_2is calculated to provide a forward packet delay (PD) measurement. On the other side, a first return packet sent from the DR is received at the intermediate node having a TSval=R_i, and measuring a timestamp of arrival (t3) of the packet at the intermediate node. A second return packet sent from the DR is received at the intermediate node from the same session and having the same TSval=R_i, and a timestamp of arrival (t4) of the packet at the intermediate node is measured. The inter-packet arrival time is calculated responsive to t_3and t_4to provide a return PD measurement. The above process is repeated for a plurality of packets in the session, repeating the steps to provide a plurality of forward PD measurements and a plurality of return PD measurements, and the forward and return PD values are processed to provide an overall PD value. In some embodiments, the packet-based communication session is a TCP/IP session, the DS comprises a UE. and the DR comprises a server. In some embodiments the forward PD value is calculated as t_2−t_1, and the return PD value is calculated as t_4−t_3. The overall PD value measured over a time interval can be calculated as the variance associated with the forward and return PD measurements during that time interval.

