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Introduction to A1 measurement in 5G 

A1 measurement is a new measurement framework for A1 interoperability testing in 5G. It is based on the existing 3GPP tests and aims to provide a 5G network with a new protocol stack for monitoring and troubleshooting services, as well as new procedures for securing the measurement instances. A1 measurement is a network quality measurement in A2, which provides the quality of service metrics for all applications running on the mobile terminal. It will be used to measure the overall cell edge throughput and latency in wireless networks, as well as support future 5G NR RATs. A1 is based on the heritage of E-UTRA uplink and Uplink (UL) measurements, with minor changes in frequency and configuration allocation. This is applicable to any UE type, which can be Pre-5G or 5G type. At the cut-through aspect of LTE, the A1 measurement will continue to be used for 5GNR coverage evaluations. 

A1 is a measurement of air interface latency, which has a direct impact on the overall user experience. A1 is defined as the time from transmission of a data or control message from the UE to receipt by the EPC. This can represent both round trip radio path latency and network processing time. A1 measurement is an essential measurement in 5G. It is mainly used for monitoring the spectrum usage of different carriers and devices, detecting any interference, and tracking the location of eNodeBs to improve the performance of mobile networks. A1 measurement is a key technology to realize efficient 5G networks. It provides a new way to calculate and estimate the performance of 5G mobile networks, especially in dynamic environments where environmental conditions are continuously changing (such as an indoor environment). The reference architecture provides high-level descriptions of various functionalities within an A1 network and specifies different solutions for radio resource management, mobility management, and application/service control. 

A1 measurement is a 5G measurement methodology. It includes situations in which an end-user device performs A-level experiments on network elements - either directly or indirectly. The A-level measurements strongly depend on the measurement method used. One example use case is concerning the gap between the coverage of eNBs and small cells in indoor environments. This use case can be formulated as a problem of a gap between coverage envelopes of eNBs and small cells. A1 measurement is used to calculate the delay and jitter for a specific receiver. It is measured by sending a reference signal (for example, the common source or common pilot channel) to both ends of an interface and measuring the time difference using that reference signal. A1 measurement is a critical component of 5G. It provides the most accurate information about the network behavior and allows for improved network scalability, enabling massive MIMO technology in an efficient way. A1 measurement is a product of the TU22 and TU23 phase specification for 5G New Radio (NR) coexistence between LTE, Wi-Fi, and 5G. 

A1 measurement purpose

The purpose of A1 measurements is to verify that the parameters used during a handover from NR to Wi-Fi/LTE can be used as parameters for a cell search. The parameters are obtained from the MAC layer. The A1 measurement is a standardized test method defined in ITU-R M.2177 for evaluating the cell characteristics of 5G NR systems. The A1 measurement is based on a propagation model called the Advanced propagation, which also defines an additional measurement solution for dual uplink/downlink MIMO. This enhanced solution is to be used for evaluating the maximum performance in cases when there are two eNodeBs or an eNodeB and an access point connected to each other directly, without requiring the use of an additional antenna array to add connectivity between eNodeBs / APs, unlike the conventional dual uplink MIMO measurements mentioned above, in which extra antennas must be added near all eNodeBs / APs with which they need to transmit/receive their signals. The A1 measurement provides an indication of the level of accuracy and stability of a channel. It is used by a UE to identify one or more channels that may be suitable for use in transmission; the conditions on these channels may vary significantly over time. 

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