JP-7856172-B2 - Communication control device, wireless access system, communication control method and program

Inventors

• 大谷 育生
• 藤本 圭
• 藤田 勝美

Assignees

• ＮＴＴ株式会社

Dates

Publication Date

20260511

Application Date

20230131

Claims (13)

1. A communication control device for processing wireless access signals, A communication quality information acquisition unit that acquires communication quality information, A processing time estimation unit calculates the estimated processing time for each CPU frequency from the acquired communication quality information, A communication control device characterized by comprising: a frequency control unit that lowers the CPU frequency below the currently set CPU frequency when the estimated processing time is less than or equal to the processing time of the time slot; and a frequency control unit that lowers the CPU frequency below the currently set CPU frequency.
2. The communication control device according to claim 1, characterized in that the communication quality information acquisition unit is an MCS (Modulation and Coding Scheme) acquisition unit that acquires the MCS Index of UL (UP Link) or DL (Down Link) in the MAC time slot as the communication quality information.
3. The communication control device according to claim 1, characterized in that the communication quality information acquisition unit is a radio wave state acquisition unit that acquires UL (UP Link) or DL (Down Link) radio wave quality information as the communication quality information.
4. The communication control device according to claim 1, characterized in that the communication quality information acquisition unit is a MAC schedule analysis unit that acquires wireless resource allocation information including MAC schedule information as the communication quality information.
5. The communication control device according to claim 1, characterized in that the communication quality information acquisition unit is a delay time acquisition unit that calculates a delay time from the measured value of the PHY-high processing time and acquires the said delay time as the communication quality information.
6. The communication control device according to claim 1, characterized in that the frequency control unit determines the CPU frequency by adding a safety factor to the CPU frequency set by the processing time estimation unit.
7. The processing time estimation unit has a learning table that associates the PHY-high processing time for each MCS Index or radio wave quality information with the CPU frequency. The communication control device according to claim 1, characterized in that the processing time estimation unit refers to the learning table and determines the lowest CPU frequency among the learning table such that the estimated processing time is less than or equal to the processing time of the time slot.
8. The processing time estimation unit has a learning table that associates the PHY-high processing time for each MCS Index or radio wave quality information with the CPU frequency. The communication control device according to claim 1, characterized in that the processing time estimation unit 113 refers to the learning table and performs feedback by rewriting the table values of the learning table based on the measured value of the PHY-high processing time.
9. An accelerator that offloads specific processing of an application to perform computation, The system includes an accelerator driver that controls the accelerator according to the accelerator settings set by the frequency control unit, The communication control device according to claim 1, characterized in that the frequency control unit determines the accelerator setting by adding a safety factor when setting the accelerator.
10. CPU cores, The uncore is a peripheral device other than the CPU core, It includes an uncore setting storage unit that stores the uncore frequency relative to the CPU core frequency, The communication control device according to claim 1, characterized in that the frequency control unit controls the uncore at an uncore frequency that does not cause the uncore to become a bottleneck, based on the setting information of the uncore setting storage unit.
11. A wireless access system comprising a base station that processes wireless access signals, and a communication control device that controls the CPU frequency of a CPU core located in the base station hardware, The communication control device is A communication quality information acquisition unit that acquires communication quality information, A processing time estimation unit calculates the estimated processing time for each CPU frequency from communication quality information, A wireless access system characterized by comprising: a frequency control unit that lowers the CPU frequency below the currently set CPU frequency within a range where the estimated processing time is less than or equal to the processing time of the time slot.
12. A communication control method for a communication control device that processes wireless access signals, The communication control device is Steps to obtain communication quality information, The steps include: calculating the estimated processing time for each CPU frequency from the acquired communication quality information; A communication control method characterized by performing the steps of: lowering the CPU frequency below the currently set CPU frequency when the estimated processing time is less than or equal to the processing time of the time slot.
13. A program for causing a computer to function as a communication control device according to any one of claims 1 to 10.

Description

This invention relates to a communication control device, a wireless access system, a communication control method, and a program. In a Radio Access Network (RAN), low-latency communication is achieved by sequentially executing data transfers at specific time intervals (time slots). Traditionally, in RANs, communication from user terminals (UEs) to the core network has been primarily achieved using dedicated equipment. In vRAN (virtual Radio Access Network), which implements RAN base stations using software and general-purpose servers, accelerators are utilized and CPU frequencies are maximized through tuning to handle demanding processing, thus meeting the strict time constraints on the order of microseconds. <vRAN> Let me explain vRAN. In mobile communication radio access systems, high latency requirements and throughput are demanded, so it has been common practice to use dedicated hardware (dedicated equipment) for base stations (BBUs) that perform radio signal processing. In recent years, with the widespread adoption of general-purpose servers (IA: Intel Architecture Servers (Intel: trademark)), the performance of these servers has dramatically improved, and mass production has made them available at low cost. As a result, there is growing interest in vRAN (Virtual Randomness Network) for performing radio signal processing of BBUs (Bandbuffer Units) in LTE (Long Term Evolution) and 5G wireless access systems using general-purpose servers. In vRAN, inexpensive and readily available general-purpose servers can be used as BBU hardware. Therefore, by using regional data centers (DCs) or communication buildings within a radius of several tens of kilometers from the antenna as centralization points and setting up server racks with multiple general-purpose servers in advance, a BBU pool can be constructed (this concept is sometimes referred to as C-RAN (Centralized-RAN)). The BBU pool has the potential advantage of enabling flexible operation, such as rapid hardware replacement (switchover) in the event of hardware failure, and dynamic scale-out/(or)-in in response to increases or decreases in traffic, because it allows for the preparation of multiple base station hardware (general-purpose servers) in advance. In wireless access systems, it is sometimes possible to separate the base station function into RU (Radio Unit), DU (Distributed Unit), and CU (Centralized Unit). This section describes the functions of RU/DU/CU. The functions of the RU include PHY-low, AD/DA conversion, iFFT, analog beamforming, and digital beamforming. The functions of the DU include PHY-high, modulation/demodulation, coding/decoding, scrambling, and MAC, and these processes are executed by the DU server. The functions of the CU include the execution of the Packet Data Convergence Protocol, Radio Resource Control, and Service Data Adaptation Protocol. In EPC/5GC mobile communications, the functions of the BBU are placed in the DU and CU, and the functions of the RRH (Remote Radio Head) that process radio frequencies (RF) are placed in the RU. Most general base stations are installed as slave stations that only have an RU as equipment, while base stations equipped with a DU and CU are called master stations and are connected to slave stations by a network called a fronthaul. Furthermore, BBU pools can also be pooled at a smaller unit than the RU, DU, or CU isolation units, such as CPU cores, accelerators, and NICs (Network Interface Cards) in a server. This section provides an overview of the vRAN system. Figure 46 is a diagram illustrating the overview of the vRAN system. As shown in Figure 46, the vRAN system (wireless access system) 1 includes a terminal (UE: User Equipment) 10, an RU 20 with an antenna (base station antenna), a DU server 30, a CU server 40, and a core network 50. In a wireless access system, the transmission timing of wireless signals between terminals and base stations is managed by the MAC (Medium Access Control) Scheduler at the base station as a resource multiplexed in the time domain and frequency domain. The DU server 30 manages this by allocating a RE (Resource Element) for each UE 10. UE10 is a wireless device such as a mobile phone terminal, and connects to RU20 via a wireless section. UE10 converts the data to be transmitted into a wireless signal and sends it to RU20. UE10 processes the wireless signal received from RU20 and restores it to the data intended by the sender. There are two types of communication between UE10 and RU20: uplink (UE10 ⇒ RU20 ⇒ DU Server 30) (hereinafter referred to as UL as appropriate) and downlink (DU Server 30 ⇒ RU20 ⇒ UE10) (hereinafter referred to as DL as appropriate). RU20 is an antenna and transceiver unit that communicates wirelessly with UE10 (hereinafter, "antenna" refers collectively to the antenna, the transceiver unit, and its power supply unit). The transmitted and received data is connected to the DU server 30, for example, by a dedicated cable. RU20 acts as a bas