Real-time processing in wireless communication systems

Abstract

A method, apparatus, and computer program product for real-time processing in a wireless communication system are disclosed. An interruption in processing of one or more first symbol packets in one or more wireless communication components is detected. A predetermined time period for delaying processing of one or more second symbol packets is determined. Processing of the one or more second symbol packets is delayed until the predetermined time period has elapsed. Thereafter, processing of the one or more second symbol packets is performed.

Description

[Technical field]

[0001] In some implementations, the subject matter of the present disclosure relates to telecommunications systems, and in particular to real-time processing in wireless communication systems such as, for example, 5G New Radio ("NR"). [Background technology]

[0002] In today's world, cellular networks provide on-demand communication capabilities to individuals and businesses. Typically, cellular networks are wireless networks that can be distributed over land areas called cells. Each cell is served by at least one fixed-location transceiver called a cell site or base station. Each cell can use a different set of frequencies than neighboring cells to avoid interference and improve service within each cell. When cells are combined, they provide wireless coverage over a wide geographic area, allowing a large number of mobile phones and other wireless devices, portable transceivers, to communicate with each other and with fixed transceivers and landlines anywhere in the network. Such communication is achieved through base stations, even when mobile transceivers move between multiple cells while transmitting and receiving. Major wireless communication providers deploy such cell sites around the world, allowing mobile phones and mobile computing devices to communicate with the public switched telephone network and the public Internet.

[0003] A mobile phone is a portable telephone that can receive and / or make voice and data calls through a cell site or transmission tower by using radio waves to transmit signals to and from the mobile phone. From the perspective of many mobile phone users, current mobile phone networks provide a limited and shared resource. In this regard, cell sites and mobile phones (handsets) can change frequencies and use low-power transmitters to allow many callers to use the network simultaneously with less interference. The coverage by a cell site may depend on a particular geographic location and / or the number of users that can potentially use the network. For example, in urban areas, the range of a cell site may be up to about a half mile, in rural areas, the range may be up to five miles, and in some areas, users may receive signals from cell sites up to 25 miles away.

[0004] Some of the digital cellular technologies used by carriers include: Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), cdmaOne, CDMA2000, Evolution-Data Optimized (EV-DO), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Digital Enhanced Cordless Telecommunications (DECT), Digital AMPS (IS-136 / TDMA), and Integrated Digital Enhanced Network (iDEN). Long Term Evolution, or 4G LTE, is a standard developed by the standards organization Third Generation Partnership Project (3GPP®) for high-speed data wireless communication for mobile phones and data terminals. Currently, 5G LTE standards are being developed and deployed. LTE is based on GSM / EDGE and UMTS / HSPA digital cellular technologies and enables increased capacity and speeds by improving the core network and using a different air interface. DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] In wireless communication systems, deploying multiple real-time workloads in a virtualized / containerized environment on a single non-uniform memory access node poses challenges in ensuring that the workloads can meet their real-time requirements. The shared resources of the underlying processor (CPU) can cause resource contention with Last Level Cache (LLC) and memory bandwidth consumption, where one workload may occupy more resources than necessary. As a result, one of the multiple workloads cannot meet its real-time requirements, adversely affecting product / application performance, causing application restarts and related service downtime. Typically, this set of issues is classified as a "noisy neighbor" problem. These issues reduce the overall service availability and reliability of multiple real-time workloads in wireless communication systems. [Means for solving the problem]

[0006] In some embodiments, the subject matter of the present disclosure relates to a computer-implemented method for real-time processing in a wireless communication system, which may include detecting an interruption in processing of one or more first symbol packets in one or more wireless communication components, determining a predetermined time period for delaying processing of one or more second symbol packets, delaying the processing of the one or more second symbol packets until the predetermined time period expires, and performing the processing of the one or more second symbol packets.

[0007] In some embodiments, the subject matter of the present disclosure may include one or more of any of the following features: In some embodiments, at least one of the detecting, determining, delaying, and resuming may be performed by a base station. The base station may include at least one communication component of one or more remote radio units, one or more air interface units, and one or more distributed units. The distributed units may be configured to interface with the air interface units for processing the first and second symbol packets.

[0008] In some embodiments, the distribution unit may be one or more virtualization distribution units, which may correspond to one or more virtual machines running on a host operating system.

[0009] In some embodiments, a first virtual machine may be configured to detect an interruption upon restart of a second virtual machine on the same host operating system.

[0010] In some embodiments, the predetermined period may be determined based on a multiple of a transmission time interval corresponding to the time for transmitting a symbol packet between the virtualization distribution unit and the air interface unit. For example, the predetermined period may be 2 milliseconds. Alternatively, the predetermined period may be 5 milliseconds. In some embodiments, the predetermined period may be N milliseconds (during which monitoring, detection and correction without service interruption may be performed), where N may correspond to the amount of time after which the end user equipment begins to notice a service degradation and / or service interruption. In some exemplary and non-limiting embodiments, N may be set as high as several hundred milliseconds.

[0011] In some embodiments, the delaying may include dequeuing the first symbol packet from a processing queue, and the first symbol packet may be dequeued and discarded by at least one of Layer 1 and Layer 2 of the wireless communication device that receives the first symbol packet.

[0012] A non-transitory computer program product (i.e., a physically embodied computer program product) is disclosed as storing instructions that, when executed by one or more data processors of one or more computing systems, cause at least one data processor to perform the operations disclosed herein. Similarly, computer systems are disclosed that may include one or more data processors and a memory coupled to the one or more data processors. The memory may store, either temporarily or permanently, instructions that cause at least one processor to perform one or more of the operations disclosed herein. Furthermore, the method may be performed by one or more data processors within a single computing system or distributed among two or more computing systems. Such computing systems may be connected to exchange data and / or commands or other instructions, etc., via one or more connections, including, but not limited to, connections via a network (e.g., the Internet, a wireless wide area network, a local area network, a wide area network, a wired network, etc.), a direct connection between one or more of the computing systems, etc.

[0013] The details of one or more variations of the subject matter disclosed herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter disclosed herein will become apparent from the following description and drawings, and from the claims.

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate certain aspects of the subject matter disclosed herein and, together with the following description, serve to explain some of the principles associated with the disclosed embodiments. [Brief description of the drawings]

[0015] [Figure 1A] FIG. 1A illustrates an exemplary conventional Long Term Evolution (LTE) communication system.

[0016] [Figure 1B] FIG. 1B illustrates further details of the exemplary LTE system shown in FIG. 1A.

[0017] [Figure 1C] FIG. 1C illustrates additional details of the evolved packet core of the exemplary LTE system shown in FIG. 1A.

[0018] [Figure 1D] FIG. 1D is a diagram illustrating an example evolved Node B (eNodeB) of the example LTE system shown in FIG. 1A.

[0019] [Diagram 2] FIG. 2 is a diagram showing further details of the eNodeB shown in FIGS. 1A to 1D.

[0020] [Diagram 3] FIG. 3 is a diagram illustrating an example virtual radio access network in accordance with some embodiments of the subject matter of this disclosure.

[0021] [Figure 4] FIG. 4 illustrates an exemplary 3GPP split architecture for providing use of higher frequency bands to its users.

[0022] [Diagram 5] FIG. 5 illustrates an example 5G wireless communication system.

[0023] [Figure 6] FIG. 6 is a diagram illustrating a 5G wireless communication system according to some embodiments of the subject matter of the present disclosure.

[0024] [Figure 7A] FIG. 7A is a diagram showing a protocol stack of the user plane.

[0025] [Figure 7B] FIG. 7B is a diagram showing a protocol stack of the control plane.

[0026] [Figure 8] FIG. 8 illustrates an example system for performing real-time processing of data (eg, data packets) according to some embodiments of the subject matter of this disclosure.

[0027] [Figure 9] FIG. 9 shows an example plot illustrating the processing of symbol packets.

[0028] [Figure 10] FIG. 10 illustrates an example process for addressing a condition detected by one or more virtual machines executing on a host operating system of a virtualization distribution unit of a base station in accordance with some embodiments of the subject matter of the present disclosure.

[0029] [Figure 11] FIG. 11 illustrates an example process for maintaining real-time (or substantially real-time) processing of symbols in a wireless communication system according to some embodiments of the disclosed subject matter.

[0030] [Figure 12] FIG. 12 is a diagram illustrating an example system according to some embodiments of the subject matter of this disclosure.

[0031] [Figure 13] FIG. 13 illustrates an example method according to some embodiments of the subject matter of this disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The subject matter of the present disclosure may provide systems and methods that may be implemented in a lower layer split architecture for wireless communication systems. Such systems may include a variety of wireless communication systems, including 5G New Radio communication systems, Long Term Evolution (LTE) communication systems, and the like.

[0033] One or more aspects of the subject matter of the present disclosure may be incorporated into transmitter and / or receiver components of a base station (e.g., gNodeB, eNodeB, etc.) in such communication systems. The following is a general discussion of Long Term Evolution and 5G New Radio communication systems. I. Long Term Evolution Communication System

[0034] 1A-1C and 2 illustrate an exemplary conventional Long Term Evolution ("LTE") communication system 100 along with various components thereof. The LTE system, or 4G LTE, as it is commercially known, conforms to a standard for high-speed data wireless communication for mobile phones and data terminals. The standard is based on GSM / EDGE ("Global System for Mobile Communications" / "Enhanced Data rates for GSM Evolution") and UMTS / HSPA ("Universal Mobile Telecommunications System" / "High Speed ​​Packet Access") network technologies. The standard was developed by the 3rd Generation Partnership Project (3GPP).

[0035] As shown in FIG. 1A, the system 100 may include an Evolved Universal Terrestrial Radio Access Network ("EUTRAN") 102, an Evolved Packet Core ("EPC") 108, and a Packet Data Network ("PDN") 101, where the EUTRAN 102 and the EPC 108 provide communication between user equipment 104 and the PDN 101. The EUTRAN 102 may include multiple Evolved Node Bs ("eNodeB" or "ENODEB" or "enodeb" or "eNB") or base stations 106(a,b,c) (see FIG. 1B) that provide communication capabilities to multiple user equipment 104(a,b,c). The user equipment 104 may be a mobile phone, a smartphone, a tablet, a personal computer, a personal digital assistant ("PDA"), a server, a data terminal, and / or any other type of user equipment, and / or any combination thereof. User equipment 104 can connect to the EPC 108, and thus to the PDN 101, via any eNodeB 106. Typically, user equipment 104 can connect to the eNodeB 106 that is closest in terms of distance. In the LTE system 100, the EUTRAN 102 and the EPC 108 work together to provide connectivity, mobility, and services to the user equipment 104.

[0036] Figure 1B shows further details of the network 100 shown in Figure 1A. As mentioned above, the EUTRAN 102 includes multiple eNodeBs 106, also called cell sites. The eNodeBs 106 provide radio functionality and perform key control functions including air link resource scheduling or radio resource management, active mode mobility or handover, and admission control of services. The eNodeBs 106 select which mobility management entity (MME, see Figure 1C) serves the user equipment 104 and are responsible for protocol functions such as header compression and encryption. The multiple eNodeBs 106 that make up the EUTRAN 102 cooperate with each other for radio resource management and handover.

[0037] Communication between the user equipment 104 and the eNodeB 106 occurs over an air interface 122 (also referred to as an "LTE-Uu" interface). As shown in FIG. 1B, the air interface 122 provides communication between the user equipment 104b and the eNodeB 106a. The air interface 122 employs Orthogonal Frequency Division Multiple Access ("OFDMA") and Single Carrier Frequency Division Multiple Access ("SC-FDMA"), a variant of OFDMA, on the downlink and uplink, respectively. OFDMA allows for the use of multiple known antenna technologies, such as Multiple Input Multiple Output ("MIMO").

[0038] The air interface 122 uses a variety of protocols, including radio resource control ("RRC") for signaling between the user equipment 104 and the eNodeB 106, and non-access stratum ("NAS") for signaling between the user equipment 104 and the MME (see FIG. 1C). In addition to signaling, user traffic is transferred between the user equipment 104 and the eNodeB 106. Both signaling (signaling) and traffic in the system 100 are carried by physical layer ("PHY") channels.

[0039] The multiple eNodeBs 106 may be interconnected with each other using X2 interfaces 130(a, b, c). As shown in FIG. 1A, the X2 interface 130a provides an interconnection between the eNodeBs 106a and 106b, the X2 interface 130b provides an interconnection between the eNodeBs 106a and 106c, and the X2 interface 130c provides an interconnection between the eNodeBs 106b and 106c. The X2 interfaces may be established between the two eNodeBs to provide an exchange of signals, which may include handover-related information as well as load- or interference-related information. The eNodeBs 106 communicate with the evolved packet core 108 via the S1 interfaces 124(a, b, c). The S1 interface 124 can be divided into two interfaces: an interface for the control plane (shown as control plane interface (S1-MME interface) 128 in FIG. 1C) and an interface for the user plane (shown as user plane interface (S1-U interface) 125 in FIG. 1C).

[0040] The EPC 108 establishes and enforces quality of service ("QoS") for user services and allows the user equipment 104 to maintain a consistent Internet Protocol ("IP") address while moving. Note that each node of the network 100 has its own IP address. The EPC 108 is designed to interoperate with legacy wireless networks. The EPC 108 is also designed to separate the control plane (i.e., signaling) and the user plane (i.e., traffic) in the core network architecture, which allows for greater flexibility in implementation and independent scalability of control and user data functions.

[0041] The architecture of the EPC 108 is dedicated to packet data and is shown in detail in Figure 1C. The EPC 108 includes a Serving Gateway (S-GW) 110, a PDN Gateway (P-GW) 112, a Mobility Management Entity ("MME") 114, a Home Subscriber Server ("HSS") 116 (the subscriber database for the EPC 108), and a Policy Control and Charging Rules Function ("PCRF") 118. Some of these (S-GW, P-GW, MME, HSS, etc.) are often grouped together into nodes according to the manufacturer's implementation.

[0042] The S-GW 110 acts as a router for IP packet data and is the bearer path anchor for user equipment in the EPC 108. Thus, when a user equipment moves from one eNodeB 106 to another during mobility operation, the S-GW 110 remains the same and the bearer path towards the EUTRAN 102 is switched to communicate with the new eNodeB 106 serving the user equipment 104. If the user equipment 104 moves to the domain of another S-GW 110, the MME 114 transfers all the bearer paths of the user equipment to the new S-GW. The S-GW 110 establishes the bearer paths of the user equipment to one or more P-GWs 112. If downstream data is received for an idle user equipment, the S-GW 110 buffers the downstream packets and requests the MME 114 to search for and re-establish the bearer path to and from the EUTRAN 102.

[0043] The P-GW 112 is a gateway between the EPC 108 (and the user equipment 104 and EUTRAN 102) and the PDN 101 (see FIG. 1A). The P-GW 112 performs functions on behalf of the user equipment as well as acting as a router for user traffic. These include allocating IP addresses to the user equipment, packet filtering of downstream user traffic so that it is placed on the appropriate bearer path, enforcing downstream QoS including data rate, etc. Depending on the services the subscriber is using, there may be multiple bearer paths for user data between the user equipment 104 and the P-GW 112. A subscriber may use services on the PDN provided by different P-GWs, in which case the user equipment has at least one bearer path established to each P-GW 112. When handing over a user equipment from one eNodeB to another, if the S-GW 110 is also changed, the bearer path from the P-GW 112 is switched to the new S-GW.

[0044] The MME 114 manages the user equipment 104 in the EPC 108, which includes managing subscriber authentication, maintaining the context of authenticated user equipment 104, establishing a data bearer path in the network for user traffic, and tracking the location of idle mobile equipment that is not detached from the network. For an idle user equipment 104 that needs to reconnect to the access network to receive downstream data, the MME 114 initiates paging to locate the user equipment and reestablish a bearer path between the EUTRAN 102. The MME 114 for a particular user equipment 104 is selected by the eNodeB 106 where the user equipment 104 initiates system access. The MME is typically part of a collection of MMEs in the EPC 108 for load sharing and redundancy purposes. In establishing a bearer path for user data, the MME 114 is responsible for selecting the P-GW 112 and S-GW 110 that constitute the termination of the data path through the EPC 108.

[0045] The PCRF 118 is responsible for policy control decision making and control of flow-based charging functions in the Policy Control Enforcement Function ("PCEF") residing in the P-GW 110. The PCRF 118 provides QoS authorization (QoS Class Identifier ("QCI") and bit rate) that determines how a particular data flow is treated in the PCEF, ensuring that this adheres to the user's subscription profile.

[0046] As mentioned above, IP services 119 are provided by PDN 101 (see FIG. 1A).

[0047] 1D illustrates an example configuration of an eNodeB 106. The eNodeB 106 may include at least one remote radio head ("RRH") 132 (typically, there may be three RRHs 132) and a baseband unit ("BBU") 134. The RRH 132 may be connected to an antenna 136. The RRH 132 and the BBU 134 may be connected using an optical interface that conforms to the Common Public Radio Interface ("CPRI") 142 standard specification. The operation of the eNodeB 106 may be characterized using the following standard parameters (and specifications): radio frequency band (Band 4, Band 9, Band 17), bandwidth (5, 10, 15, 20 MHz), access method (downlink: OFDMA; uplink: SC-OFDMA), antenna technology (downlink: 2x2 MIMO, uplink: 1x2 Single Input Multiple Output ("SIMO")), number of sectors (up to 6), maximum transmit power (60W), maximum transmission speed (downlink: 150 Mb / s, uplink: 50 Mb / s), S1 / X2 interface (1000Base-SX, 1000Base-T), mobile environment (up to 350 km / h). The BBU 134 may be responsible for digital baseband signal processing, S1 line termination, X2 line termination, call processing, supervisory control processing, etc. IP packets received from the EPC 108 (not shown in FIG. 1D ) may be modulated into digital baseband signals and transmitted to the RRH 132. Conversely, digital baseband signals received from the RRH 132 may be demodulated into IP packets and transmitted to the EPC 108.

[0048] The RRH 132 may transmit and receive wireless signals using the antenna 136. The RRH 132 may convert (with a converter ("CONV") 140) digital baseband signals from the BBU 134 to radio frequency ("RF") signals and power amplify (with an amplifier ("AMP") 138) for transmission to the user equipment 104 (not shown in FIG. 1D). Conversely, RF signals received from the user equipment 104 are amplified (with AMP 138) and converted (with CONV 140) to digital baseband signals for transmission to the BBU 134.

[0049] FIG. 2 illustrates additional details of an exemplary eNodeB 106. The eNodeB 106 includes multiple layers: LTE Layer 1 202, LTE Layer 2 204, and LTE Layer 3 206. LTE Layer 1 includes the physical layer ("PHY"). LTE Layer 2 includes Medium Access Control ("MAC"), Radio Link Control ("RLC"), and Packet Data Convergence Protocol ("PDCP"). LTE Layer 3 includes various functions and protocols such as Radio Resource Control ("RRC"), dynamic resource allocation, eNodeB measurement configuration and provisioning, radio admission control, connection mobility control, and radio resource management ("RRM"). The RLC protocol is an automatic repeat request ("ARQ") fragmentation protocol used over the cellular air interface. The RRC protocol handles the signaling of the LTE Layer 3 control plane between the user equipment and the EUTRAN. The RRC includes functions of connection establishment and release, system information broadcast, radio bearer establishment / reconfiguration and release, mobility procedures for RRC connections, paging notification and release, and outer loop power control. The PDCP performs IP header compression and decompression, user data transfer, and radio bearer sequence number retention. The BBU 134 shown in FIG. 1D may include LTE layers L1 to L3.

[0050] One of the main functions of the eNodeB 106 is radio resource management, which includes scheduling of air interface resources, both uplink and downlink, control of bearer resources, and admission control for the user equipment 104. As an agent of the EPC 108, the eNodeB 106 is responsible for forwarding paging messages used to locate the mobile device when it is idle. The eNodeB 106 also performs communication of common control channel information with the ground, header compression, encryption and decryption of user data transmitted with the ground, and establishment of handover reporting and trigger criteria. As mentioned above, the eNodeB 106 may cooperate with other eNodeBs 106 via the X2 interface for handover and interference management purposes. The eNodeB 106 communicates with the MME of the EPC via the S1-MME interface and with the S-GW using the S1-U interface. Additionally, the eNodeB 106 exchanges user data with the S-GW via the S1-U interface. The eNodeBs 106 and the EPC 108 have a many-to-many relationship to support load balancing and redundancy between MMEs and S-GWs. The eNodeB 106 selects an MME from a group of MMEs so that the load is shared by multiple MMEs and congestion can be avoided. II.5G NR wireless communication network

[0051] In some embodiments, the subject matter of the present disclosure relates to 5G New Radio ("NR") communication systems. 5G NR is the next telecommunications standard beyond the 4G / IMT-Advanced standard. 5G networks provide higher capacity than current 4G, enabling more mobile broadband users per area unit, and consuming higher and / or unlimited amounts of data in gigabytes per month and per user. This allows users to stream high-definition media for hours per day using their mobile devices, even in places where there are no Wi-Fi networks. 5G networks provide better support for device-to-device communications, lower cost, lower latency, lower battery consumption, etc. than 4G devices. Such networks provide data rates of tens of megabits per second for many users, data rates of 100 Mb / s in metropolitan areas, 1 Gb / s simultaneously for users in enclosed areas (e.g., office floors), many simultaneous connections of wireless sensor networks, improved spectral efficiency, improved coverage, improved signal processing efficiency, latency of 1-10 ms, and lower latency than existing systems.

[0052] 3 illustrates an example virtual radio access network 300. The network 300 may provide communication between various components, including base stations (e.g., eNodeB, gNodeB) 301, radio equipment 307, centralized unit 302, digital unit 304, and wireless devices 306. The components in the system 300 may be communicatively coupled to a core using backhaul links 305. The centralized unit ("CU") 302 may be communicatively coupled to a distributed unit ("DU") 304 using midhaul connections 308. The radio frequency ("RU") component 306 may be communicatively coupled to the DU 304 using fronthaul connections 310.

[0053] In some embodiments, the CU 302 may provide intelligent communication capabilities to one or more DU units 304. The units 302, 304 may include one or more base stations, macro base stations, micro base stations, remote radio heads, etc., and / or any combination thereof.

[0054] In a lower layer split architecture environment, the CPRI bandwidth requirement for NR can be hundreds of Gb / s. CPRI compression can be implemented at the DU and RU (see Figure 3). In 5G communication systems, compressed CPRI over Ethernet frames is called eCPRI and is the recommended fronthaul interface. This architecture allows for standardization of fronthaul / midhaul, which may include upper layer splitting (e.g., option 2 or option 3-1 (upper / lower RLC split architecture)) and fronthaul with L1-split architecture (option 7).

[0055] In some embodiments, the lower layer split architecture (e.g., option 7) may include receiver in uplink, joint processing across multiple transmission points (TPs) for both DL / UL, and transport bandwidth and delay requirements to facilitate deployment. Additionally, the lower layer split architecture of the presently disclosed subject matter may include splitting between cell level processing and user level processing, which may include cell level processing at the remote unit ("RU") and user level processing at the DU. Additionally, using the lower layer split architecture of the presently disclosed subject matter, frequency domain samples may be transmitted over the Ethernet fronthaul, where the frequency domain samples may be compressed to reduce the fronthaul bandwidth.

[0056] 4 illustrates an example communication system 400 that may implement 5G technology and provide its users with the use of higher frequency bands (e.g., greater than 10 GHz). The system 400 may include a macro cell 402 and small cells 404 and 406.

[0057] The mobile device 408 may be configured to communicate with one or more of the small cells 404, 406. The system 400 enables splitting of the control plane (C-plane) and user plane (U-plane) between the macro cell 402 and the small cells 404, 406, where the C-plane and U-plane are using different frequency bands. In particular, the small cells 402, 404 may be configured to utilize higher frequency bands when communicating with the mobile device 408. The macro cell 402 may utilize existing cellular bands for C-plane communications. The mobile device 408 may be communicatively coupled via a U-plane 412, where the small cells (e.g., the small cell 406) may provide higher data rates and more flexible / cost / energy-efficient operation. The macro cell 402 may maintain good connectivity and mobility via the C-plane 410. Additionally, in some cases, the LTE PUCCH and the NR PUCCH may transmit on the same frequency.

[0058] FIG. 5 illustrates an example 5G wireless communication system 500 according to some embodiments of the subject matter of this disclosure. The system 500 may be configured with a lower layer split architecture according to option 7-2. The system 500 may include a core network 502 (e.g., 5G Core) and one or more gNodeBs (or gNBs), where the gNBs may have a centralized unit gNB-CU. The gNB-CU may be logically split into a control plane portion, gNB-CU-CP, 504, and one or more user plane portions, gNB-CU-UP, 506. The control plane portion 504 and the user plane portion 506 may be configured to be communicatively coupled using an E1 communication interface 514 (defined in the 3GPP standard). The control plane portion 504 may be configured to be responsible for executing the RRC and PDCP protocols of the wireless stack.

[0059] The control plane and user plane portions 504, 506 of the centralized unit of the gNB may be configured to be communicatively coupled to one or more distributed units (DUs) 508, 510 according to a lower layer split architecture. The distributed units 508, 510 may be configured to execute the upper part of the RLC, MAC and PHY layer protocols of the radio stack. The control plane portion 504 may be configured to be communicatively coupled to the distributed units 508, 510 using an F1-C communication interface 516, and the user plane portion 506 may be configured to be communicatively coupled to the distributed units 508, 510 using an F1-U communication interface 518. The distributed units 508, 510 may be coupled to one or more remote radio units (RUs) 512 via a fronthaul interface 520, which communicate with one or more user equipment (not shown in FIG. 5). The remote radio unit 512 may be configured to execute lower portions of the PHY layer protocol and provide antenna functionality to the remote unit for communication with user equipment (similar to the description above in connection with Figures 1A-2).

[0060] FIG. 6 illustrates a 5G wireless communication system 600 according to some embodiments of the subject matter of the present disclosure. The system 600 may be part of the system 500 illustrated in FIG. 5. The system 600 may be configured to include one or more centralized units (CU) 602, one or more distributed units (DU) 604(a, b), one or more radio units (RU) 606(a, b, c), and one or more remote radio heads (RRH) 608(a, b, c, d, e, f). The units 602-608 may be communicatively coupled using one or more interfaces as described above.

[0061] In some embodiments, the CU 602 may be communicatively coupled to the DU 604a and DU 604b. In turn, the distributed unit 604a may be communicatively coupled to the remote units 606a and 606b, whereby the unit 606a may be coupled to two remote radio heads 608a and 608b, and the unit 606b may be coupled to one remote radio head 608c. The distributed unit 604b may be coupled to the remote unit 606c, which in turn may be coupled to three remote radio heads 608d, 608e, and 608e. The system 600 shown in FIG. 6 may be configured as a virtualized and disaggregated radio access network (RAN) architecture, whereby layers L1, L2, L3 and radio processing may be virtualized and disaggregated in the centralized unit(s), the distributed unit(s) and the radio unit(s).

[0062] 7A-7B show further details of example protocol stacks in a 5G wireless communication system. In particular, FIG. 7A illustrates a user plane protocol stack 700, and FIG. 7B illustrates a control plane protocol stack 710. Portions of the protocol stacks are illustrated for both an example user equipment 702 and a base station (or a portion thereof), e.g., a gNodeB or gNB, 704. The user plane protocol stack 700 may include PHY, MAC, RLC, and PDCP layers. The control plane protocol stack 710 may include PHY, MAC, RLC, PDCP, RRC, and NAS (non-access stratum, a portion of which may be incorporated into the 5G core control network 706 as shown in FIG. 7B).

[0063] The protocol stack may include Layer 1, Layer 2, and Layer 3. Layer 1 is a physical (PHY) layer. Layer 2 may include MAC, RLC, and PDCP. Layer 3 is an RRC layer, as shown in Figures 7A to 7B.

[0064] The functions of the PHY layer in a 5G communication network may include error detection of transport channels and instructions to higher layers, FEC encoding / decoding of transport channels, hybrid ARQ soft combining, rate matching of coded transport channels to physical channels, mapping of coded transport channels to physical channels, power weighting of physical channels, modulation / demodulation of physical channels, frequency / time synchronization, radio characteristic measurement and instructions to higher layers, MIMO antenna processing, digital / analog beamforming, RF processing, and other functions.

[0065] The MAC sublayer of Layer 2 may perform beam management, random access procedures, mapping between logical channels and transport channels, concatenation of multiple MAC Service Data Units (SDUs) belonging to one logical channel to a transport block (TB), multiplexing / demultiplexing of SDUs belonging to a logical channel with TBs delivered from the physical layer to the transport channel, reporting of scheduling information, error correction by HARQ, prioritization between logical channels of one UE, prioritization between UEs using dynamic scheduling, transport format selection, and other operations. The functions of the RLC sublayer may include forwarding of packet data units (PDUs) from higher layers, error correction by ARQ, reordering of data PDUs, detection of duplication and protocol errors, re-establishment, etc. The PDCP sublayer may be responsible for forwarding of user data, various functions during the re-establishment procedure, retransmission of SDUs, discarding SDUs in the uplink, forwarding of control plane data, etc.

[0066] The RRC sublayer of Layer 3 may perform functions such as broadcasting system information to the NAS and AS, establishing, maintaining and releasing RRC connections, security, establishing, configuring, maintaining and releasing point-to-point radio bearers, mobility functions, reporting, etc. III. Real-time Processing in Wireless Communication Systems

[0067] In some embodiments, the subject matter of the present disclosure may be configured to perform real-time processing of data in a wireless communication system, such as LTE, 5G NR, and / or any other wireless communication environment. Figure 8 illustrates an example system 800 for performing real-time processing of data (e.g., data packets) according to some embodiments of the subject matter of the present disclosure. System 800 may be incorporated into one or more of the systems described above in connection with Figures 1A-7B.

[0068] The system 800 may include one or more air interface units 802(a, b) capable of providing an interface between one or more user equipment (not shown in FIG. 8 ) and one or more distributed units (DUs) 804. The distributed units 804 may be virtualized distributed units (vDUs) (as described above) and may operate as virtual machines (VMs) and / or containerized microservices executable in real time on a host operating system (OS). For example, as shown in FIG. 8 , the vDU virtual machine 804 may be configured to interface with two air interface units 802(a, b). Each air interface unit 802 may be configured to operate three respective antennas or sectors 806 (a, b, c, d, e, f). Thus, in the example shown in FIG. 8 , the vDU virtual machine 804 may be configured to operate six sectors. As can be appreciated, other configurations of the vDU virtual machines 804 and their operating capabilities are possible.

[0069] In some embodiments, the interface between the vDU 804 and the air interface unit 802 may include an Ethernet interface that may be configured to transmit / receive one or more data symbols 810 per antenna carrier (AxC) of each cell 808 (as shown in FIG. 8, there are six cells 808 with four transceivers each corresponding to 24 AxC antennas). For each transmission in each cell with a 1 ms subframe structure, there may be 14 symbol packets (packets) 812 that may be transmitted within each time transmission interval (TTI) 814. In each TTI 814, the symbol packets 812 may be spaced 72 microseconds apart. As a result of such close spacing between symbols, signals may be transmitted / received with low latency. To ensure that low latency is maintained, the vDU 804 may be configured to perform data packet processing in real time or substantially real time.

[0070] As mentioned above, the vDU 804 may run on a physical host operating system, and the processing components of the host operating system may be adjusted to maintain low latency for each application executed by the vDU 804. However, since the host operating system includes a kernel (i.e., the core computer program of the host operating system that completely controls everything in the system), periodically the host may be configured to execute a big lock or kernel lock, which is a lock used by the kernel to provide concurrency control and / or other system management mode (SMP) operations typically required by Symmetric Multiprocessing (SMP) systems. When the kernel big lock is executed or a condition requiring SMM occurs, the vDU virtual machine 804 may be configured to exit and stop executing (i.e., not send / receive data). The host operating system may take control of the system for a short period of time or for an extended period of time. In the latter case, a "stretch" or gap in time between symbols / slots may be observed when the vDU virtual machine 804 resumes operation. Such a "stretch" may refer to the amount of time that has elapsed between a first point in time ("then") when the vDU virtual machine 804 stopped operating by taking a final snapshot of the system time, and a second point in time ("now") when the vDU virtual machine 804 resumes operation. If the time that has elapsed between the first and second points in time is greater than a predetermined time (e.g., several hundred microseconds), the vDU virtual machine 804 may have to be restarted as it can no longer keep up with the real-time processing of data packets.

[0071] Since one or more vDU virtual machines 804 may be associated with the same host operating system, operations performed by one vDU virtual machine (e.g., rebooting, restarting, etc.) may affect the operation of other vDU virtual machines (e.g., causing them to reboot, restart, stop operating, etc.). This may also result in the virtual machines "stretching." This scenario is sometimes referred to as a "noisy neighbor" scenario. Furthermore, stretching may be caused by a variety of errors, including virtual machine remapping errors, deployment issues, virtual machine instantiation issues, test protocols running on the host operating system, and other issues.

[0072] Some example "stretch" conditions may include, but are not limited to, testing port redundancy of multi-hole ports in a base station. Such testing may create delays in real-time processing of active vDU virtual machines on or across certain non-uniform memory access nodes, causing the vDU virtual machines to exceed the 1 ms latency for LTE processing and, as a result, experience instability, thereby causing the "stretch" condition.

[0073] Another exemplary "stretch" condition may include rebooting virtualized signal processing units on adjacent virtual machines on the same non-uniform memory access node or on adjacent non-uniform memory access nodes of the same server running the same host OS in SMP mode of operation. The reboot generates errors in the kernel log indicating that the virtual function ports associated with the vDU virtual machine being reinitialized are still in a reset state. This causes instability in adjacent virtual machines that were otherwise operational.

[0074] An additional example of "stretching" may include rebooting a nearby vDU virtual machine (e.g., an operating system level reboot), which impacts other vDU virtual machines on the same non-uniform memory access node. Because the same operating system is shared between non-uniform memory access nodes (i.e., sockets) on the same server, this type of vDU virtual machine reboot can cause problems for all vDU virtual machines on the node(s).

[0075] Additionally, a "stretch" condition can be caused by a direct memory access (DMA) remapping error generated by the host operating system, as seen in the kernel logs. When this occurs, all vDU virtual machines on that server can be placed in an unstable state.

[0076] Additionally, instantiation of a vDU virtual machine may cause noisy neighbor problems with other running vDU virtual machines because the underlying host operating systems as well as other components are identical across servers. As can be appreciated, other conditions may also cause interruptions in operation in one or more vDU virtual machines.

[0077] Figure 9 illustrates an example plot 900 showing the processing of symbols. As shown in Figure 9, there are 14 symbols (e.g., corresponding to the 14 symbols shown in Figure 8) being processed during each transmission interval 902. The processing of the symbols appears smooth until an interruption or stretch is detected at time 904. At that point, the processing is no longer smooth (e.g., as indicated by the jagged edges on the plot).

[0078] In some embodiments, the subject matter of this disclosure can provide a mechanism for detecting delays due to a "stretch" between a first point in time (e.g., "at that time" or before an event is detected) and a second point in time (e.g., "now" or after an event is detected). This mechanism can be implemented in the vDU, for example, as part of its software layer, and can provide a way to accommodate such stretches while maintaining real-time or substantially real-time processing by the vDU virtual machine without interruption (e.g., for the stream of fronthaul packets that use the interface between the vDU 804 and the RIU 802).

[0079] In some embodiments, the RIU 804 may include a resiliency mechanism that may be configured to generate dummy symbol packets when it fails to receive a symbol packet for a particular antenna carrier (AxC) of a particular sector. Such dummy packets may be configured to keep the CPRI interface toward the remote radio unit (RRU) synchronized. This may ensure that the air interface unit 802 is always synchronized to the air CPRI interface.

[0080] In some embodiments, upon detecting a “stretch” condition (e.g., reboot of another vDU virtual machine, etc.), the vDU 804 may be configured to skip processing one or more symbols that would normally be generated during one or more transmission time intervals (TTIs). After skipping, the vDU 804 may be configured to attempt to resynchronize with the air interface unit 802. The resynchronization attempt may be performed after a predefined period of time that may correspond to the number of skipped TTIs. For example, the vDU 804 may be configured to skip processing symbols during two transmission time intervals upon detection of a “stretch” condition (e.g., corresponding to a point in time “at that time”). This means that the vDU 804 skips processing symbols for about 2 ms and attempts to resynchronize with the TIU 802 after about 2 ms. In some exemplary and non-limiting embodiments, the vDU 804 may be configured to skip processing symbols for a 5 ms interval and attempts to resynchronize with the RIU 802 after 5 ms. As can be appreciated, any other period (less than or greater than 2 ms or 5 ms) may be used for the purpose of skipping processing symbols and attempting resynchronization.

[0081] Such skipping may ensure that a particular sector can remain operational after a predefined period of detected "stretching". This is a non-intrusive procedure and does not affect the RRC connected state of the UE in the particular sector(s). This means that the sector can remain operational and the user equipment can remain connected in the sector.

[0082] 10 illustrates an example process 1000 for addressing a condition detected by one or more virtual machines executing on a host operating system of a virtualization distribution unit of a base station, according to some embodiments of the subject matter of this disclosure. The process 1000 may be performed between Layer 1 1002 and Layer 2 1004 components. Layers 1 and 2 may be responsible for preparing data for scheduling within each transmission time interval (TTI), which may be, for example, up to 1 millisecond. As mentioned above, there are a predetermined number of symbol packets that may be received from an external entity during each TTI and that may be received in a queue of Layer 1.

[0083] During normal operation, when a packet reaches Layer 1 1002 and is processed, the packet may be dequeued from the Layer 1 queue. Layer 1 may then transmit an identification of the TTI (e.g., TTI_Indication('N'), where N may correspond to a particular TTI) to Layer 2 1004 so that Layer 2 can perform appropriate processing.

[0084] At 1006, Layer 1 1002 may detect one or more interruption scenarios, such as those described above. This may result in CPU starvation for real-time applications at Layer 1 / Layer 2, which may cause the actual elapsed time to be greater than the TTI time. When this occurs, Layer 1 1002 may detect a large number of backlogged (e.g., unprocessed / undequeued) symbol packets in the queue at time N+1. Layer 1 may then enter skip / resynchronize TTI mode at 1008 and send an appropriate indication (e.g., TTI_Indication('N+1')[SkipResynchTTIMode='Enable']) to Layer 2 so that Layer 2 can also enter this mode.

[0085] At 1010, Layer 1 may enter a resiliency mode (e.g., as described above for generating dummy symbol packets upon failure to receive a symbol packet for a particular AxC for a particular sector) and skip processing a TTI of symbols, while continuing to dequeue symbol packets. Layer 1 may still continue processing essential tasks. Layer 2 may perform the same tasks. Furthermore, Layers 1 and 2 may continue the same for the next predefined number of TTIs (e.g., five skippable TTIs, as shown in FIG. 10). At each next TTI skip, Layer 1 may send an appropriate notification to Layer 2 to inform it that a TTI processing skip is being performed (e.g., TTI_Indication('N+2'), TTI_Indication('N+3'), TTI_Indication('N+4'), TTI_Indication('N+5')).

[0086] At 1012, Layer 1 may exit the skip / resynchronization TTI mode, dequeue the symbol packet, and inform Layer 2 that it is exiting this mode (e.g., TTI_Indication('N+6')[SkipResynchTTIMode]=['Disable']) so that Layer 2 may exit this mode. At this point, Layer 1 and Layer 2 may return to normal symbol processing.

[0087] FIG. 11 illustrates an example process 1100 for maintaining real-time (or substantially real-time) processing of symbols in a wireless communication system, according to some embodiments of the subject matter of this disclosure. Process 1100 may be performed by one or more components of a distributed unit and / or a virtualized distributed unit. In some example embodiments, process 1100 may be performed by a host operating system of the distributed unit, which may be configured to host one or more virtual machines. At 1102, one or more vDU virtual machines may be configured to detect the occurrence of a disruption in the processing of symbols during one or more transmission time intervals (e.g., as shown in FIG. 9). The disruption may be a result of one or more scenarios described above.

[0088] At 1104, the vDU virtual machine experiencing the interruption may be configured to skip processing of symbols for a predetermined period of time. The predetermined period of time may correspond to one or more transmission time intervals (TTIs) during which the processing of symbols occurs. During the skip, one or more components of Layer 1 may be configured to dequeue any symbol packets but continue processing essential tasks (as described above with respect to FIG. 10).

[0089] At 1106, after a predetermined period of time, the vDU virtual machine may revert to normal processing of symbol packets.

[0090] In some embodiments, the subject matter of the present disclosure may be configured to be implemented in a system 1200, as shown in FIG. 12. The system 1200 may include one or more processors 1210, memory 1220, storage device 1230, and input / output device 1240. Each of the components 1210, 1220, 1230, and 1240 may be interconnected using a system bus 1250. The processor 1210 may be configured to process instructions for execution within the system 600. In some embodiments, the processor 1210 may be a single-threaded processor. In other embodiments, the processor 1210 may be a multi-threaded processor. The processor 1210 may be further configured to process instructions stored in the memory 1220 or the storage device 1230, including receiving or transmitting information via the input / output device 1240. The memory 1220 may store information within the system 1200. In some embodiments, the memory 1220 may be a computer-readable medium. In alternative embodiments, memory 1220 may be a volatile memory unit. Moreover, in some embodiments, memory 1220 may be a non-volatile memory unit. Storage device 1230 may be capable of providing mass storage for system 1200. In some embodiments, storage device 1230 may be a computer-readable medium. In alternative embodiments, storage device 1230 may be a floppy disk drive, a hard disk drive, an optical disk drive, a tape drive, a non-volatile solid-state memory, or any other type of storage device. Input / output device 1240 may be configured to provide input / output operations for system 1200. In some embodiments, input / output device 1240 may include a keyboard and / or a pointing device. In alternative embodiments, input / output device 1240 may include a display device for displaying a graphical user interface.

[0091] FIG. 13 illustrates an example method 1300 according to some implementations of the subject matter of this disclosure. The process 1300 may be performed by the system 800 illustrated in FIG. 8. At 1302, an interruption in the processing of one or more first symbol packets in one or more wireless communication components may be detected. The interruption may be caused by a "noisy neighbor" (e.g., one virtual machine rebooting on a host operating system causing other virtual machines to reboot). The communication components may include a virtualization distribution unit. At 1304, a predetermined period (e.g., 2 TTI, 5 TTI, etc.) for a delay in the processing of one or more second symbol packets may be determined. The second symbol packets may be processed after the packets for the first symbols are dequeued / discarded. At 1306, the processing of the second symbol packets may be delayed until the predetermined period has elapsed. At 1308, the processing of the second symbol packets may be resumed.

[0092] In some embodiments, the subject matter of the present disclosure may include one or more of any of the following features: In some embodiments, at least one of the detecting, determining, delaying, and resuming may be performed by a base station. The base station may include at least one communication component of one or more remote radio units, one or more air interface units, and one or more distributed units. The distributed units may be configured to interface with the air interface units for processing the first and second symbol packets.

[0093] In some embodiments, the distribution unit may be one or more virtualization distribution units. The virtualization distribution units may correspond to one or more virtual machines running on a host operating system.

[0094] In some embodiments, a first virtual machine may be configured to detect an interruption upon restart of a second virtual machine on the same host operating system.

[0095] In some embodiments, the predetermined period may be determined based on a multiple of a transmission time interval corresponding to the time for transmitting a symbol packet between the virtualization distribution unit and the air interface unit. For example, the predetermined period may be 2 milliseconds. Alternatively, the predetermined period may be 5 milliseconds. In some embodiments, the predetermined period may be N milliseconds (during which monitoring, detection and correction without service interruption may be performed), where N may correspond to an amount of time after which end user equipment may begin to notice service degradation and / or service interruption. In some exemplary and non-limiting embodiments, N may be as high as several hundred milliseconds.

[0096] In some embodiments, the delaying may include dequeuing the first symbol packet from a processing queue. The first symbol packet may be dequeued and discarded by at least one of Layer 1 and Layer 2 of the wireless communication device that receives the first symbol packet.

[0097] The systems and methods disclosed herein can be embodied in various forms, including, for example, data processing devices such as computers, including databases, digital electronic circuits, firmware, software, or combinations thereof. Moreover, the above-mentioned features and other aspects and principles of the disclosed embodiments of the present disclosure can be implemented in various environments. Such environments and related applications can be specially constructed to perform the various processes and operations according to the disclosed embodiments, or they can include general-purpose computers or computing platforms selectively activated or reconfigured by code to provide the required functions. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and can be implemented by any suitable combination of hardware, software, and / or firmware. For example, various general-purpose machines can be used with programs written in accordance with the teachings of the disclosed embodiments, or it may be more convenient to construct specialized apparatus or systems to perform the required methods and techniques.

[0098] The systems and methods disclosed herein may be implemented as a computer program product, i.e., a computer program embodied in an information carrier, e.g., in a machine-readable storage device or a propagated signal, for execution by or to control the operation of a data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. The computer program may be written in any form of programming language, including compiled or interpreted languages, and may be arranged in any form, such as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. The computer program may be deployed to be executed on one computer, on multiple computers at one site, or distributed across multiple sites and interconnected by a communications network.

[0099] As used herein, the term "user" can refer to any entity, including a person or a computer.

[0100] Although ordinal numbers such as first and second may relate to order in some contexts, ordinal numbers as used in this disclosure do not necessarily imply order. For example, ordinal numbers may be used simply to distinguish one item from another, e.g., to distinguish a first event from a second event, but do not necessarily imply a chronological order or a fixed system of reference (just as a first event in one paragraph herein may be different from a first event in another paragraph herein).

[0101] The above description is intended to illustrate, but not limit, the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims.

[0102] These computer programs, also referred to as programs, software, software applications, applications, components, or codes, include machine instructions for a programmable processor and may be implemented in a high-level procedural and / or object-oriented programming language, and / or assembly / machine language. As used herein, the term "machine-readable medium" refers to any computer program product, apparatus, and / or device, such as, for example, magnetic disks, optical disks, memories, programmable logic devices (PLDs), etc., used to provide machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal used to provide machine instructions and / or data to a programmable processor. A machine-readable medium may store such machine instructions non-transiently, such as, for example, a non-transient solid-state memory or a magnetic hard drive or any equivalent storage medium. A machine-readable medium may alternatively or additionally store such machine instructions in a transitory manner, such as, for example, a processor cache or other random access memory associated with one or more physical processor cores.

[0103] To provide for interaction with a user, the subject matter disclosed herein can be implemented on a computer having a display device, such as, for example, a cathode ray tube (CRT) or liquid crystal display (LCD) monitor, for displaying information to the user, and a keyboard and pointing device, such as, for example, a mouse or trackball, by which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user. For example, feedback provided to the user can be any form of sensory feedback, such as, for example, visual feedback, auditory feedback, or tactile feedback, and input from the user can be received in any form, including, but not limited to, acoustic, speech, or tactile input.

[0104] The subject matter disclosed herein may be implemented as a computing system including a back-end component, such as, for example, one or more data servers, or a computing system including a middleware component, such as, for example, one or more application servers, or a front-end component, such as, for example, one or more client computers having a graphical user interface or a web browser through which a user can interact with an embodiment of the subject matter disclosed herein, or any combination of such back-end, middleware, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication, such as, for example, a communications network. Examples of communications networks include, but are not limited to, a local area network ("LAN"), a wide area network ("WAN"), and the Internet.

[0105] A computing system may include clients and servers. Clients and servers are generally, though not only, remote from each other and typically interact through a communication network. The relationship of clients and servers arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0106] The embodiments disclosed in the above description do not represent all embodiments consistent with the subject matter disclosed herein. Rather, they are merely some examples consistent with aspects related to the disclosed subject matter. Although some variations have been described in detail above, other modifications or additions are possible. In particular, further features and / or variations may be provided in addition to those disclosed herein. For example, the implementations described above may be directed to various combinations and subcombinations of the disclosed features, and / or combinations and subcombinations of some further features described above. Furthermore, the logic flow depicted in the accompanying figures and / or described herein does not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other embodiments may be within the scope of the following claims.

Claims

1. 1. A method performed by a communications system including a plurality of virtual machines running as communications components on a host operating system, comprising: Detecting a stretching condition associated with processing of one or more first symbol packets in at least one of the plurality of virtual machines; determining a period of time for a delay in processing the one or more second symbol packets; ceasing processing of the one or more second symbol packets until the period has elapsed; and resuming processing of the one or more second symbol packets. The method according to claim 1, further comprising:

2. 2. The method of claim 1 , At least one of the plurality of virtual machines operates in a base station. A method comprising:

3. 3. The method of claim 2, the base station includes at least one of: one or more remote radio units, one or more air interface units, and one or more distributed units; A method comprising:

4. 4. The method of claim 3, the one or more distributed units are configured to interface with the one or more air interface units for processing the one or more first and second symbol packets. A method comprising:

5. 4. The method of claim 3, the one or more distributed units being one or more virtualized distributed units; A method comprising:

6. 2. The method of claim 1 , a first virtual machine in the plurality of virtual machines is configured to detect the stretch condition upon a restart of a second virtual machine in the plurality of virtual machines; A method comprising:

7. 6. The method of claim 5, the period is determined based on a multiple of a transmission time interval corresponding to a time for transmitting a symbol packet between the one or more virtualization distribution units and the one or more air interface units; A method comprising:

8. 8. The method of claim 7, The period is 2 milliseconds. A method comprising:

9. 2. The method of claim 1 , the stopping includes dequeuing one or more first symbol packets from a processing queue. A method comprising:

10. 10. The method of claim 9, the one or more first symbol packets are dequeued and discarded by at least one of a layer 1 and a layer 2 of a wireless communication device receiving the one or more first symbol packets. A method comprising:

11. at least one programmable processor; and a non-transitory machine-readable medium storing instructions that, when executed by the at least one programmable processor, cause the at least one programmable processor to perform operations, The operations performed are performed by a plurality of virtual machines running as communicating components on a host operating system; Detecting a stretching condition associated with processing of one or more first symbol packets in at least one of the plurality of virtual machines; determining a period of time for a delay in processing the one or more second symbol packets; ceasing processing of the one or more second symbol packets until the period has elapsed; and resuming processing of the one or more second symbol packets. An apparatus comprising:

12. 12. The apparatus of claim 11, At least one of the plurality of virtual machines operates in a base station. An apparatus comprising:

13. 13. The apparatus of claim 12, the base station includes at least one of: one or more remote radio units, one or more air interface units, and one or more distributed units; An apparatus comprising:

14. 14. The apparatus of claim 13, the one or more distributed units are configured to interface with the one or more air interface units for processing the one or more first and second symbol packets. An apparatus comprising:

15. 14. The apparatus of claim 13, the one or more distributed units being one or more virtualized distributed units; An apparatus comprising:

16. 12. The apparatus of claim 11, a first virtual machine in the plurality of virtual machines is configured to detect the stretch condition upon a restart of a second virtual machine in the plurality of virtual machines; An apparatus comprising:

17. 16. The apparatus of claim 15, the period is determined based on a multiple of a transmission time interval corresponding to a time for transmitting a symbol packet between the one or more virtualization distribution units and the one or more air interface units; An apparatus comprising:

18. 18. The apparatus of claim 17, The period is 2 milliseconds. An apparatus comprising:

19. 12. The apparatus of claim 11, the stopping includes dequeuing one or more first symbol packets from a processing queue. An apparatus comprising:

20. 20. The apparatus of claim 19, the one or more first symbol packets are dequeued and discarded by at least one of a layer 1 and a layer 2 of a wireless communication device receiving the one or more first symbol packets. An apparatus comprising:

21. 1. A computer program storing instructions that, when executed by at least one programmable processor, cause the at least one programmable processor to perform operations, comprising: The operations performed are performed by a communications system including a plurality of virtual machines running as communications components on a host operating system; Detecting a stretching condition associated with processing of one or more first symbol packets in at least one of the plurality of virtual machines; determining a period of time for a delay in processing the one or more second symbol packets; ceasing processing of the one or more second symbol packets until the period has elapsed; and resuming processing of the one or more second symbol packets. A computer program comprising:

22. 22. A computer program according to claim 21, comprising: At least one of the plurality of virtual machines operates in a base station. A computer program comprising:

23. 23. A computer program according to claim 22, comprising: the base station includes at least one of: one or more remote radio units, one or more air interface units, and one or more distributed units; A computer program comprising:

24. 24. A computer program according to claim 23, comprising: the one or more distributed units are configured to interface with the one or more air interface units for processing the one or more first and second symbol packets. A computer program comprising:

25. 24. A computer program according to claim 23, comprising: the one or more distributed units being one or more virtualized distributed units; A computer program comprising:

26. 22. A computer program according to claim 21, comprising: a first virtual machine in the plurality of virtual machines is configured to detect the stretch condition upon a restart of a second virtual machine in the plurality of virtual machines; A computer program comprising:

27. 26. A computer program according to claim 25, comprising: the period is determined based on a multiple of a transmission time interval corresponding to a time for transmitting a symbol packet between the one or more virtualization distribution units and the one or more air interface units; A computer program comprising:

28. 28. A computer program according to claim 27, comprising: The period is 2 milliseconds. A computer program comprising:

29. 22. A computer program according to claim 21, comprising: the stopping includes dequeuing one or more first symbol packets from a processing queue. A computer program comprising:

30. 30. A computer program according to claim 29, comprising: the one or more first symbol packets are dequeued and discarded by at least one of a layer 1 and a layer 2 of a wireless communication device receiving the one or more first symbol packets. A computer program comprising:

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