# Patent

## Title
Systems and methods for scheduling of data packets based on delay tolerance of applications

## Abstract

A base station, system, method, and computer program product are disclosed for transmitting data packets received by the base station. According to one aspect, the base station includes a first buffer configured to store data packets received by the base station, a second buffer configured to store data packets that are scheduled for transmission by the base station, and a computer processor, operatively coupled to the first buffer and the second buffer. The computer processor is configured to inspect a data packet to determine an application type of the data packet, determine a delay tolerance associated with the data packet based on the determined application type, determine a channel condition of a communication session with the user device, move the data packet from the first buffer to the second buffer based on the determined delay tolerance and the determined channel condition, and transmit data packets stored in the second buffer.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority to U.S. Provisional Patent Application No. 61/804,886, filed on Mar. 25, 2013, and entitled “Application Based Store and Forward in an Evolved Node B,” and incorporates its disclosure herein by reference in its entirety.


TECHNICAL FIELD
Embodiments of the present subject matter relate to systems and methods for scheduling of data packets based on a delay tolerance of applications.
SUMMARY OF THE EMBODIMENTS
According to one aspect, a base station transmitting data packets is described. The base station includes a first buffer configured to store data packets received by the base station, a second buffer configured to store data packets that are scheduled for transmission by the base station, and a computer processor, operatively coupled to the first buffer and the second buffer. The computer processor is configured to inspect a data packet to determine an application type of the data packet, determine a delay tolerance associated with the data packet based on the determined application type, determine a channel condition of a communication session with the user device, move the data packet from the first buffer to the second buffer based on the determined delay tolerance and the determined channel condition, and transmit data packets stored in the second buffer.
According to some implementations, the base station is configured to determine a delay budget for the data packet, schedule the data packet for transmission if the channel condition corresponds to a first channel condition and store the data packet for a time period that is equal to the delay budget prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.
According to some implementations, the computer processor is configured to detect a change of the channel condition from the second channel condition to the first channel condition, and wherein the computer processor is configured to move the data packet to the second buffer upon detection of the change.
According to some implementations, the computer processor is configured to detect that the data packet corresponds to a delay intolerant application or delay tolerant application, and wherein the computer processor is configured to schedule the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.
According to some implementations, the computer processor is configured to transmit the data packets corresponding to delay intolerant applications with lower modulation than data packets corresponding to delay tolerant applications.
According to some implementations, the computer processor is configured to transmit the data packets corresponding to delay intolerant applications with higher redundancy than data packets corresponding to delay tolerant applications.
According to some implementations, the base station includes an evolved node (eNodeB) base station, wherein the first buffer includes an input buffer of the base station, and wherein the second buffer includes a scheduling buffer of the base station.
According to some implementations, the computer processor is configured to inspect the data packet to determine at least one of an application type of the data packet and an application state corresponding to the data packet, and wherein the application state includes one of a data establishment state and a data transfer state.
According to some implementations, the computer processor is configured to transmit the data packet to a remote radio head, and wherein the remote radio head includes a radio transmitter and a radio receiver.
According to some implementations, the computer processor is configured to perform a shallow packet inspection of the data packet, and based on the shallow packet inspection, perform a deep packet inspection of the data packet.
According to another aspect, a method for coordinating transmission of data packets received by the base station is described. The method includes storing data packets received by the base station in a first buffer, determining a channel condition of a communication session with the user device, inspecting a data packet to determine an application type of the data packet, determining a delay tolerance associated with the data packet based on the determined application type, moving the data packet from the first buffer to a second buffer based on the determined delay tolerance and the determined channel condition, and transmitting the data packets stored in the second buffer.
According to some implementations, the method includes determining a delay budget for the data packet, scheduling the data packet for transmission if the channel condition corresponds to a first channel condition, and storing the data packet for a time period that is equal to the delay timer prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.
According to some implementations, the method includes detecting a change of the channel condition from the second channel condition to the first channel condition, and wherein the moving the data packet to the second buffer upon detection of the change.
According to some implementations, the method includes detecting that the data packet corresponds to a delay intolerant application or delay tolerant application, and scheduling the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.
According to some implementations, the method includes transmitting data packets corresponding to delay intolerant applications with lower modulation than data packets corresponding to delay tolerant applications.
According to some implementations, the method includes transmitting data packets corresponding to delay intolerant applications with higher redundancy than data packets corresponding to delay tolerant applications.
According to some implementations, the method includes inspecting the data packet to determine at least one of an application type of the data packet and an application state corresponding to the data packet, and wherein the application state includes one of a data establishment state and a data transfer state.
According to some implementations, the method includes transmitting the data packet to a remote radio head, and wherein the remote radio head includes a radio transmitter and a radio receiver.
According to some implementations, the method includes performing a shallow packet inspection of the data packet, and based on the shallow packet inspection, perform a deep packet inspection of the data packet.
According to another aspect, a non-transitory computer readable medium having stored thereon a computer program product having instructions is described. The instructions are configured to cause processing circuitry of a base station to store data packets received by the base station in a first buffer, inspect a data packet to determine an application type of the data packet, determine a delay tolerance associated with the data packet based on the determined application type, determine a channel condition of a communication session with the user device, move the data packet from the first buffer to a second buffer based on the determined delay tolerance and the determined channel condition, and transmit data packets stored in the second buffer.
According to some implementations, the computer program product includes instructions configured to cause the processing circuitry to determine a delay budget for the data packet, schedule the data packet for transmission if the channel condition corresponds to a first channel condition, and store the data packet for a time period that is equal to the delay budget prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.
According to some implementations, the computer program product includes instructions configured to cause the processing circuitry to detect a change of the channel condition from the second channel condition to the first channel condition, and move the data packet to the second buffer upon detection of the change.
According to some implementations, the computer program product includes instructions configured to cause the processing circuitry to detect that the data packet corresponds to a delay intolerant application or delay tolerant application, and schedule the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.
According to some implementations, the shallow packet inspection includes inspecting an IP header of the data packet, and wherein a deep packet inspection includes inspecting a payload of the data packet.
According to some implementations, a deep packet inspection may include an inspection of one or more of layers 1-7 of an open systems interconnect (OSI) model data packet, while a shallow packet inspection may include an inspection of a header and/or data in layer 7 of an OSI model data packet.
According to some implementations, the first channel condition corresponds to a channel condition in which the user device is located in a first RF reception area, and the second channel condition corresponds to a condition in which the user device is located in a second RF reception area, and wherein the first RF reception area has greater RF reception than the second RF reception area.
According to some implementations, the channel condition may be based on an examination of one or more of the Channel Quality Index (CQI) and signal to noise plus interference ratio (SINR) determined at the base station for the communication session.
According to some implementations, the base station is part of a macro network. According to some implementations, the base station includes an intelligent baseband unit (iBBU) and intelligent RRH (iRRH), such that the packet inspection is performed by an actively cooled iBBU which is separate from a passively cooled iRRH.
According to some implementations, the base station includes a memory having stored therein settings for different applications types, including the delay budget and delay tolerance of the different application types. These settings may be used to set the delay budget for a data packet having an application type that matches the application type stored in the base station's memory. In some implementations, the delay budget corresponds to a time period (e.g., measured in milliseconds, seconds, minutes, or the like) for which the data packet can be delayed based on the information stored in the base station memory. In some implementations, these settings may be determined based on analytics performed on various applications which analyze, for example, the duration of each transaction, direction of communication, transport protocol used (e.g., TCP/SCTP, UDP), number of bytes per transaction, and/or interval between consecutive transactions.
According to some implementations, when the channel condition is below the threshold, the delay budget is utilized to determine when the data packet should be moved from the input buffer to the scheduling buffer. If the data packet is associated with a delay tolerant application, then the data packet is moved to the scheduling buffer based on the determined delay budget of the application. If the channel conditions change such that the user equipment transitions to a good RF reception area while the data packet is being delayed based on the determined delay budget of the data packet, the data packet is moved to the scheduling buffer without reference to any extended delay budget that is applied based on the application type of the data packet. According to some implementations, if the application is delay intolerant, then the application is moved to the scheduling buffer without additional delay.
According to some implementations, movement of the data packet from the input buffer to the scheduling buffer may be performed based on tagging or encapsulating the data packet with additional data, for example, such as by applying a PDCP header to the data packet. For data packets associated with delay tolerant applications that are to be transmitted to user devices in a poor RF reception area, the application of the tag or encapsulation of the data packet is delayed based on the delay tolerance of the application.
Articles are also described that comprise a tangibly embodied machine-readable medium embodying instructions that, when performed, cause one or more machines (e.g., computers, etc.) to result in operations described herein. Similarly, computer systems are also described that can include a processor and a memory coupled to the processor. The memory can include one or more programs that cause the processor to perform one or more of the operations described herein. Additionally, computer systems may include additional specialized processing units that are able to apply a single instruction to multiple data points in parallel.
The details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. Other features and advantages of the subject matter described herein will be apparent from the description and drawings, and from the claims.



BRIEF DESCRIPTION OF THE DRAWINGS
Some of the embodiments of the present disclosure will be described with reference to the following figures. It should be appreciated that the figures are provided for exemplary purposes. Items appearing in multiple figures are indicated by the same reference number in all the figures in which they appear.
FIG. 1A illustrates an example of a long term evolution (“LTE”) communications system;
FIG. 1B illustrates example implementations of the LTE system shown in FIG. 1A;
FIG. 1C illustrates an example network architecture of the LTE system shown in FIG. 1A;
FIG. 1D illustrates an example structure of an evolved node B (eNodeB) base station according to some implementations;
FIG. 2 illustrates an example structure of functional layers of an evolved node B (eNodeB) base station and an interface to a core network of the LTE system shown in FIGS. 1A-1D;
FIG. 3 illustrates another example structure of functional layers of an evolved node B (eNodeB) base station of the LTE system shown in FIGS. 1A-1D;
FIG. 4 illustrates an example of a base station coordinating communication between a user equipment and an application server based on different radio conditions according to some implementations;
FIG. 5 illustrates an example of a base station for coordinating communication between a user equipment and an application server according to some implementations;
FIG. 6 illustrates another example of a base station for coordinating communication between a user equipment and an application server according to some implementations;
FIG. 7 is a flowchart of a method of coordinating communication between a user equipment and an application server according to some implementations.



DETAILED DESCRIPTION OF SOME OF THE EMBODIMENTS
The present subject matter generally relates to coordination of packet data transmission in a mobile telecommunication system, and more particularly to scheduling of data packets based on a delay threshold associated with different applications and variations in a channel state condition of a communication session. To address the deficiencies of currently available solutions, one or more implementations of the current subject matter provide long term evolution radio access network having an intelligent capability with respect to the applications to which various data packets correspond. While the methods and systems described herein are with reference to an LTE system, and in some instances an evolved node B (eNodeB) base station in a radio access network (“RAN”) or a centralized cloud radio access network (“C-RAN”), the methods and systems described herein are applicable to other types of communication systems.
An LTE system is governed by a standard for wireless communication of high-speed data for mobile telephones and data terminals. The standard is based on the GSM/EDGE (“Global System for Mobile Communications”/“Enhanced Data rates for GSM Evolution”) as well as UMTS/HSPA (“Universal Mobile Telecommunications System”/“High Speed Packet Access”) network technologies. The standard is developed by the 3GPP® (“3rd Generation Partnership Project”).
FIG. 1A illustrates an example of a long term evolution (“LTE”) communications system 100. FIG. 1B illustrates example implementations of the LTE system shown in FIG. 1A. As shown in FIG. 1A, the system 100 can 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 EPC 108 provide communication between a user equipment 104 and the PDN 101. The EUTRAN 102 can include a plurality of evolved node B's (“eNodeB” or “ENB”) or base stations 106 (a, b, c) (as shown in FIG. 1B) that provide communication capabilities to a plurality of user equipment 104(a, b, c). The user equipment 104 can be a mobile telephone, a smartphone, a table, 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. The user equipment 104 can connect to the EPC 108 and eventually, the PDN 101, via any eNodeB 106. Typically, the user equipment 104 can connect to the nearest, in terms of distance, eNodeB 106. In the LTE system 100, the EUTRAN 102 and EPC 108 work together to provide connectivity, mobility and services for the user equipment 104.
With reference to FIG. 1B, the EUTRAN 102 may include a plurality of eNodeBs 106, also known as cell sites. The eNodeBs 106 provides radio functions and performs key control functions including scheduling of air link resources or radio resource management, active mode mobility or handover, and admission control for services.
FIG. 1C illustrates an example network architecture of the LTE system shown in FIG. 1A. As shown in FIG. 1C, the eNodeBs 106 are responsible for selecting which mobility management entities (MMEs) will serve the user equipment 104 and for protocol features like header compression and encryption. The eNodeBs 106 that make up an EUTRAN 102 collaborate with one another for radio resource management and handover as shown in FIG. 1C.
With reference to FIG. 1C, communication between the user equipment 104 and the eNodeB 106 occurs via an air interface 122 (also known as “LTE-Uu” interface). As shown in FIG. 1b, the air interface 122 provides communication between user equipment 104b and the eNodeB 106a. The air interface 122 uses Orthogonal Frequency Division Multiple Access (“OFDMA”) and Single Carrier Frequency Division Multiple Access (“SC-FDMA”), an OFDMA variant, on the downlink and uplink respectively. OFDMA allows use of multiple known antenna techniques, such as, Multiple Input Multiple Output (“MIMO”).
The air interface 122 uses various protocols, which include a radio resource control (“RRC”) for signaling between the user equipment 104 and eNodeB 106 and non-access stratum (“NAS”) for signaling between the user equipment 104 and MME (as shown in FIG. 1c). In addition to signaling, user traffic is transferred between the user equipment 104 and eNodeB 106. Both signaling and traffic in the system 100 are carried by physical layer (“PHY”) channels.
Multiple eNodeBs 106 can be interconnected with one another using an X2 interface 130(a, b, c). As shown in FIG. 1a, X2 interface 130a provides interconnection between eNodeB 106a and eNodeB 106b; X2 interface 130b provides interconnection between eNodeB 106a and eNodeB 106c; and X2 interface 130c provides interconnection between eNodeB 106b and eNodeB 106c. The X2 interface can be established between two eNodeBs in order to provide an exchange of signals, which can include a load- or interference-related information as well as handover-related information. The eNodeBs 106 communicate with the evolved packet core 108 via an S1 interface 124(a, b, c). The S1 interface 124 can be split into two interfaces: one for the control plane (shown as control plane interface (S1-MME interface) 128 in FIG. 1C) and the other for the user plane (shown as user plane interface (S1-U interface) 125 in FIG. 1C).
The EPC 108 establishes and enforces Quality of Service (“QoS”) for user services and allows user equipment 104 to maintain a consistent internet protocol (“IP”) address while moving. It should be noted that each node in the network 100 has its own IP address. The EPC 108 is designed to interwork with legacy wireless networks. The EPC 108 is also designed to separate control plane (i.e., signaling) and user plane (i.e., traffic) in the core network architecture, which allows more flexibility in implementation, and independent scalability of the control and user data functions.
The EPC 108 architecture is dedicated to packet data and is shown in more detail in FIG. 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 (a subscriber database for the EPC 108), and a policy control and charging rules function (“PCRF”) 118. Some of these (such as S-GW, P-GW, MME, and HSS) are often combined into nodes according to the manufacturer's implementation.
The S-GW 110 functions as an IP packet data router and is the user equipment's bearer path anchor in the EPC 108. Thus, as the user equipment moves from one eNodeB 106 to another during mobility operations, the S-GW 110 remains the same and the bearer path towards the EUTRAN 102 is switched to talk to 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 will transfer all of the user equipment's bearer paths to the new S-GW. The S-GW 110 establishes bearer paths for the user equipment to one or more P-GWs 112. If downstream data are received for an idle user equipment, the S-GW 110 buffers the downstream packets and requests the MME 114 to locate and reestablish the bearer paths to and through the EUTRAN 102.
The P-GW 112 is the gateway between the EPC 108 (and the user equipment 104 and the EUTRAN 102) and PDN 101 (shown in FIG. 1a). The P-GW 112 functions as a router for user traffic as well as performs functions on behalf of the user equipment. These include IP address allocation for the user equipment, packet filtering of downstream user traffic to ensure it is placed on the appropriate bearer path, enforcement of downstream QoS, including data rate. Depending upon the services a subscriber is using, there may be multiple user data bearer paths between the user equipment 104 and P-GW 112. The subscriber can use services on PDNs served by different P-GWs, in which case the user equipment has at least one bearer path established to each P-GW 112. During handover of the user equipment from one eNodeB to another, if the S-GW 110 is also changing, the bearer path from the P-GW 112 is switched to the new S-GW.
The MME 114 manages user equipment 104 within the EPC 108, including managing subscriber authentication, maintaining a context for authenticated user equipment 104, establishing data bearer paths in the network for user traffic, and keeping track of the location of idle mobiles that have not detached from the network. For idle user equipment 104 that needs to be reconnected to the access network to receive downstream data, the MME 114 initiates paging to locate the user equipment and re-establishes the bearer paths to and through the EUTRAN 102. MME 114 for a particular user equipment 104 is selected by the eNodeB 106 from which the user equipment 104 initiates system access. The MME is typically part of a collection of MMEs in the EPC 108 for the purposes of load sharing and redundancy. In the establishment of the user's data bearer paths, the MME 114 is responsible for selecting the P-GW 112 and the S-GW 110, which will make up the ends of the data path through the EPC 108.
The PCRF 118 is responsible for policy control decision-making, as well as for controlling the flow-based charging functionalities in the policy control enforcement function (“PCEF”), which resides in the P-GW 110. The PCRF 118 provides the QoS authorization (QoS class identifier (“QCI”) and bit rates) that decides how a certain data flow will be treated in the PCEF and ensures that this is in accordance with the user's subscription profile. As stated above, the IP services 119 are provided by the PDN 101 (as shown in FIG. 1A).
According to some implementations, the LTE network includes splitting the base station functionalities into a baseband unit (BBU), which performs, in particular, the scheduling and the baseband processing functions, and a number of remote radio heads (RRHs) responsible for RF transmission and/or reception of signals. The baseband processing unit is typically located at the center of the cell and is connected via optical fiber to the RHs. This approach allows a baseband processing unit to manage different radio sites in a central manner. Furthermore, having geographically separated RHs controlled from the same location enables either centralized baseband processing units jointly managing the operation of several radio sites, or the exchange of very low-latency coordination messages among individual baseband processing units.
The open base station architecture initiative (OBSAI) and the common public radio interface (CPRI) standards introduced standardized interfaces separating the base station server and the RRH part of a base station by an optical fiber.
FIG. 1D illustrates an example structure of an evolved node B (eNodeB) base station 106 according to some implementations. The eNodeB 106 can include at least one remote radio head (“RRH”) 132 (for example, there can be three RRH 132) and a baseband unit (“BBU”) 134. The RRH 132 can be connected to antennas 136. The RRH 132 and the BBU 134 can be connected using an optical interface that is compliant with common public radio interface (“CPRI”) 142 standard specification. The operation of the eNodeB 106 can be characterized using standard parameters and specifications for radio frequency band, bandwidth, access scheme (e.g., downlink: OFDMA; uplink: SC-OFDMA for LTE), antenna technology, number of sectors, maximum transmission rate, S1/X2 interface, and/or mobile environment. For example, these values may be set based on standards and specifications defined for LTE and/or a next generation architecture. The BBU 134 can be responsible for digital baseband signal processing, termination of S1 line, termination of X2 line, call processing and monitoring control processing. IP packets that are received from the EPC 108 (not shown in FIG. 1d) can be modulated into digital baseband signals and transmitted to the RRH 132. Conversely, the digital baseband signals received from the RRH 132 can be demodulated into IP packets for transmission to EPC 108.
The RRH 132 can transmit and receive wireless signals using antennas 136. The RRH 132 can convert (using converter (“CONV”) 140) digital baseband signals from the BBU 134 into radio frequency (“RF”) signals and power amplify (using amplifier (“AMP”) 138) them for transmission to user equipment 104 (not shown in FIG. 1d). Conversely, the RF signals that are received from user equipment 104 are amplified (using AMP 138) and converted (using CONV 140) to digital baseband signals for transmission to the BBU 134.
FIG. 2 illustrates an example structure of functional layers of an evolved node B (eNodeB) base station and an interface to a core network of the LTE system shown in FIGS. 1A-1D. The eNodeB 106 includes a plurality of layers: LTE layer 1 202, LTE layer 2 204, and LTE layer 3 206. The LTE layer 1 includes a physical layer (“PHY”). The LTE layer 2 includes a medium access control (“MAC”), a radio link control (“RLC”), a packet data convergence protocol (“PDCP”). The LTE layer 3 includes various functions and protocols, including a radio resource control (“RRC”), a dynamic resource allocation, eNodeB measurement configuration and provision, a radio admission control, a connection mobility control, and radio resource management (“RRM”). Each of these layers are discussed in further detail below.
FIG. 3 illustrates another example structure of functional layers of an evolved node B (eNodeB) base station of the LTE system shown in FIGS. 1A-1D. The system 300 can be implemented as a centralized cloud radio access network (“C-RAN”). The system 300 can include at least one intelligent remote radio head (“iRRH”) unit 302 and an intelligent baseband unit (“iBBU) 304. The iRRH 302 and iBBU 304 can be connected using Ethernet fronthaul (“FH”) communication 306 and the iBBU 304 can be connected to the EPC 108 using backhaul (“BH”) communication 308. The user equipment 104 (not shown in FIG. 3) can communicate with the iRRH 302.
In some implementations, the iRRH 302 can include the power amplifier (“PA”) module 312, the radio frequency (“RF”) module 314, LTE layer L1 (or PHY layer) 316, and a portion 318 of the LTE layer L2. The portion 318 of the LTE layer L2 can include the MAC layer and can further include some functionalities/protocols associated with RLC and PDCP, as will be discussed below. The iBBU 304 can be a centralized unit that can communicate with a plurality of iRRH and can include LTE layer L3 322 (e.g., RRC, RRM, etc.) and can also include a portion 320 of the LTE layer L2. Similar to portion 318, the portion 320 can include various functionalities/protocols associated with RLC and PDCP. Thus, the system 300 can be configured to split functionalities/protocols associated with RLC and PDCP between iRRH 302 and the iBBU 304.
One of the functions of the eNodeB 106 referred to in Layer 3 of FIG. 1C is radio resource management (“RRM”), which includes scheduling of both uplink and downlink air interface resources for user equipment 104, control of bearer resources, and admission control. The RRM function is to ensure efficient use of the available network resources. In particular, RRM in E-UTRAN provides a means to manage (e.g., the ME and assign, reassign, and release) radio resources in single and multi-cell environments. RM may be treated as a central application at the eNB responsible for interworking between different protocols (RC, S1AP, and X2AP) so that messages can be properly transferred to different nodes across Uu, S1, and X2 interfaces. RM may interface with operation and management functions in order to control, monitor, audit, or reset the status due to errors at a protocol stack. Radio admission control: The RAC functional module accepts or rejects requests for the establishment of new radio bearers.
The RRM includes modules for radio bearer control (RBC). The RBC functional module manages the establishment, maintenance, and release of radio bearers. The RRM also includes modules for connection mobility control (CMC) The CMC module manages radio resources in the idle and connected modes. In the idle mode, this module defines criteria and algorithms for cell selection, reselection, and location registration that assist the UE in selecting or camping on the best cell. In addition, the eNB broadcasts parameters that configure the UE measurement and reporting procedures. In the connected mode, this module manages the mobility of radio connections without disruption of services.
The RRM may also include modules for dynamic resource allocation (DRA) and/or packet scheduling (PS). The task of DRA or PS is to allocate and de-allocate resources (including physical resource blocks) to user and control-plane packets. The scheduling function typically considers the QoS requirements associated with the radio bearers, the channel quality feedback from the UEs, buffer status, inter-cell/intra-cell interference condition, and the like. The DRA function may take into account the restrictions or preferences on some of the available resource blocks or resource-block sets due to inter-cell interference coordination (ICIC) considerations.
The RRM may also include modules for inter-cell interference coordination (ICIC), load balancing, Inter-RAT radio resource management, and subscriber profile ID (SPID).
The eNodeB 106, as an agent for the EPC 108, is responsible for the transfer of paging messages that are used to locate mobiles when they are idle. The eNodeB 106 also communicates common control channel information over the air, header compression, encryption and decryption of the user data sent over the air, and establishing handover reporting and triggering criteria. As stated above, the eNodeB 106 can collaborate with other eNodeB 106 over the X2 interface for the purposes of handover and interference management. The eNodeBs 106 communicate with the EPC's MME via the S1-MME interface and to the S-GW with the S1-U interface. Further, the eNodeB 106 exchanges user data with the S-GW over the S1-U interface. The eNodeB 106 and the EPC 108 have a many-to-many relationship to support load sharing and redundancy among MMEs and S-GWs. The eNodeB 106 selects an MME from a group of MMEs so the load can be shared by multiple MMEs to avoid congestion.
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, or the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
As discussed above with reference to FIG. 1B, a wireless communication network may include a number of network entities, such as base stations, that can support communication for a number of mobile entities/devices, such as, for example, user equipments (UEs) or access terminals (ATs). A mobile entity may communicate with a base station via a downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.
The 3rd Generation Partnership Project (3GPP®) Long Term Evolution (LTE) represents a major advance in cellular technology as an evolution of Global System for Mobile communications (GSM) and Universal Mobile Telecommunications System (UMTS). The LTE physical layer (PHY) provides a way to convey both data and control information between a base station, such as an evolved Node B (eNB), and a mobile entity, such as a UE, with increased spectral efficiency and throughput.
In the context of LTE, information may be delivered among network entities and mobile entities as media access control (MAC) protocol data units (PDUs) and radio link control (RLC) PDUs, wherein a given RLC PDU may include at least one RLC service data unit (SDU) or RLC SDU segment. In unicast, the maximum RLC SDU size is specified in a Packet Data Convergence Protocol (PDCP).
In general, a radio access network (RAN) implements a radio access technology. Conceptually, it resides between a device such as a mobile phone, a computer, or any remotely controlled machine and provides connection with its core network (CN). Depending on the standard, mobile phones and other wireless connected devices are varyingly known as user equipment (UE), terminal equipment, mobile station (MS), and so forth. The RAN functionality is typically provided by a silicon chip residing in a node such a eNodeB which resides between the CN and the UE. RAN is used by GSM/UMTS/LTE systems, e.g., for example, GERAN (GSM RAN), UTRAN (UMTS Terrestrial RAN), and E-UTRAN (Enhanced UTRAN) are the GSM, UMTS, and LTE radio access networks.
The radio access network including the base stations provided therein is responsible for handling all radio-related functionality including scheduling of radio resources. The core network may be responsible for routing calls and data connections to external networks.
The scheduler in a base station, such as an eNodeB, is generally responsible for assigning radio resources to all UEs and radio bearers both in uplink and downlink. The scheduler in an eNodeB allocates radio resource blocks (which are the smallest elements of resource allocation) to users for predetermined amounts of time. Generally, a resource block in an LTE system corresponds to one sub-carrier over one OFDM symbol.
Data packets in a communication network may correspond to different applications having different, and in some instances, non-standardized formats for the underlying data payload. Without knowledge of the data packet payload, and its corresponding application, coordination of communication of a data packet is provided in a generic fashion. At the base station, such as an eNodeB, assignment of radio resource blocks occurs at approximately 1 ms intervals. Detection of packet data and corresponding applications outside of the base station, such as using devices in the core network or at the user device, cannot accurately account for changes in the channel conditions that occur at the 1 ms intervals at which the base station assigns radio resource blocks. For example, a base station, such as an eNodeB, may decide the type of modulation encoding mechanism for a data packet transmission, for example, using quadrature amplitude modulation QAM—including 16-QAM, 64-QAM, or the like) and/or quadrature phase shift keying (QPSK) every 1 ms. Such decisions are based on the channel conditions present during the time slice at which the base station is assigning the radio resource blocks.
Implementation of application aware scheduling of data packets in the base station involves a software intensive system. In one example of the application awareness capability as will be described in greater detail below with reference to FIGS. 4-7, a Deep Packet Inspection (DPI) function is performed by the base station (e.g., eNodeB) for inspecting data packets at any of the layers (e.g., from layer 3 (L3) to layer 7 (application layer)). The packet inspection is utilized by the base station to make inferences and/or determinations based on, for example, rule sets provisioned in the base station. Based on these inferences derived from the packet inspection, the processing to be applied on a data packet is determined. As an example, if the data packet contains an IM message, and the rule set indicates a detection of a specific type of IM message, the packet inspection will have to first detect that the packet contains an IM message, and then inspect the packet payload to determine if the particular type of IM message matches the rule set. If there is a match, a packet inspection processor will apply a particular process as indicated by the rule set, e.g., mark the packet for priority treatment for scheduling by the base station and/or utilize a particular delay threshold for the data packet as defined in the rule set. This type of packet inspection functionality implementation requires a particular hardware design and CPU capacity to sustain the compute demand on a per packet basis. Therefore, according to some implementations, in order to implement an application aware scheduler in the base station (e.g., eNodeB), the implementation of and requirements for a DPI capability are utilized to determine the base station design. As one implementation, with returned reference to FIG. 3, the base station for a macro network, such as a 3G or 4G LTE network, is split between the intelligent baseband unit (iBBU) 304 and intelligent RRH (iRRH) 302, such that the packet inspection would be performed by an actively cooled iBBU 304 which is separate from a passively cooled iRRH 302. Other implementations may also be provided utilizing processors that are capable of performing the software intensive packet inspection processes while complying with the thermal constraint of the processors and the node.
According to another implementation, packet inspection capability may be implemented outside of the base station, e.g., at a Packet Data Network Gateway (PDN-GW), and/or a dedicated node designed to perform DPI in the core network or access network responsible for doing the packet inspection and inferences. In this implementation, the inference based on the packet inspection may then be conveyed to the base station (e.g., eNodeB) in order to process the data packet accordingly. In this implementation, the time gap between detection of the data packet, inspection/determination of the inference (e.g., application type), and the processing by the base station is greater than in the implementation in which packet inspection occurs at the base station. Moreover, the core network nodes do not have base station (e.g., eNodeB) control plane (RRC) and Radio Resource Management (RRM) functionality to make the correct inference and/or determination for a given packet. For example, knowledge of the level of radio resource availability which is in the RRM and the number of active users camped on a eNodeB which is in the RRC modules are essential for a packet inspection processor to appropriately mark the packet for scheduling.
Implementing the packet inspection at the base station as described according to some implementations overcomes these challenges by locating the DPI function with inspection determination functions performed by the same hardware that hosts the base station's control plane (RRC) and Radio Resource Management (RRM) functions.
According to some implementations, a base station includes modules and/or processors for inspecting a data packet to determine an application type of the data packet, and based on the application type, determine a delay threshold for the data packet. The delay threshold may be utilized by the base station in conjunction with the detection of channel state conditions in order to determine whether the data packet should be scheduled for transmission, or if the data packet should be stored and forwarded after a predetermined time interval or when channel conditions improve.
FIG. 4 illustrates an example of a base station coordinating communication between a user equipment and an application server based on different radio conditions according to some implementations. The base station may correspond to an eNodeB, such as an eNodeB as shown and described above with reference to FIGS. 1B-1D, 2, and 3. The base station as shown in FIG. 4 includes a base band unit 404 and a radio head 402. In the case of a C-RAN architecture such as that shown in FIG. 3, the base station is split between the intelligent baseband unit (iBBU) 304 and intelligent RRH (iRRH) 302 unit as shown in FIG. 3.
The base station may be configured to communicate with a user equipment 403. The user equipment 403 may be located in a relatively good RF reception area 401A or a relatively poor RF reception area 401B. For example, when a user moves with the user equipment to an elevator or underground facility, the user equipment 403 may transition from a good RF connection area 401A to a poor RF connection area 401B. The base station may detect this transition and treat data packets that are to be transmitted to the user equipment accordingly. For example, as shown in FIG. 4, for a delay tolerant application, the base band unit 404 may buffer and wait for the user equipment to move out of the poor RF reception area 401B as shown in block 405. In some implementations, the base band unit 404 may additionally or alternatively start a buffer timer Tb, which may be based on the delay budget of the packets in the buffer. In some implementations, once the user equipment 403 transitions back to a good RF reception area 401A, the base station may send the data packet to the user equipment and stop the buffer time Tb as shown in block 407. If the buffer time reaches a predetermined limit, the base station may be configured to attempt to transmit the data packet to the user equipment even if the user equipment has not yet transitioned back to a good RF reception area 401A.
In the case of a delay intolerant application, the base station may schedule the data packet for transmission utilizing a more conservative approach as shown in block 409. For example, the base station may schedule the data packet utilizing a lower modulation coding scheme and/or by increasing redundancy bits in transmission of the data packet.
An example of a delay tolerant application may be an email application, while an example of a delay intolerant application may be an Instant Messaging (IM) application. Other examples and designations of delay tolerant and delay intolerant applications may be set by a user and/or service provider by storing settings in the user equipment, application server, and/or base station. In some implementations, data packet transmission may be monitored and analyzed continuously by an analytics server in order to determine delay tolerance and intolerance of various applications. This delay tolerance information may be provided to the base station in order to define the settings that the base station is to utilize in determining which applications are to be treated as delay tolerant relative to other applications which are to be treated as delay intolerant. For example, the network operator may run analytics on unknown applications to determine their delay tolerance behaviors. The statistics gathered in this process may include the duration of each transaction, direction of communication, transport protocol used (e.g. TCP/SCTP, UDP), number of bytes per transaction, and/or interval between consecutive transactions.
The functions described with reference to blocks 405, 407, and 409 may be performed by one or more modules and/or processors that are part of the base station. Examples of such modules and/or processors will be described in greater detail below with reference to FIGS. 5 and 6.
In some implementations, different applications may be assigned with different levels of delay tolerance by setting different buffer timers Tb for the different applications. For example, a first buffer time Tb1 may be set for a first application type, a second buffer time Tb2 may be set for a second application type, and a third buffer time Tb3 may be set for a third application type, where Tb1<Tb2<Tb3. Buffer timer settings and application type treatment settings may be stored in a memory at the base station, and/or may be transmitted to the base station by an application server or other service provider network.
FIG. 5 illustrates an example of a base station 506 for coordinating communication between a user equipment 504 and an application server 508 according to some implementations. The base station 506 includes a memory 550, an input buffer 552, a pre-scheduling processor 556, a packet inspection processor 554, a scheduling buffer 558, and a scheduling processor 560. While shown as separate components in FIG. 5, the processors, memories, and buffers may be integrated in one or more processing components. In some implementations, the pre-scheduling processor 552, the packet inspection processor 554, and/or the packet scheduling processor 560 may be provided as software modules in a processor that is specifically programmed to implement the functions described herein with reference to these processors.
In some implementations, the packet inspection processor 554 may include one or more server class CPUs (e.g., Intel Xeon®) or embedded CPUs (e.g., Cavium Octeon® or Broadcom XLP®). In some implementations, the packet scheduling processor 560 and pre-scheduling processor may include one or more digital signal processors (DSPs), for example TI Keystone II® or Cavium Octeon Fusion® processors. The pre-scheduling processor 552, packet inspection processor 554, and/or packet scheduling processor 560 may include software and/or firmware for programming these devices along with any hardware components (e.g., logic gates, accelerators, memory, or the like) that these processors may include.
The memory 550 may be coupled to one or more of the processors in the base station 506 and may include various settings for the base station, including, for example, delay tolerance, buffer timer, and/or other application specific treatment settings as discussed above with reference to FIG. 4. The input buffer 552 may be configured to store data packets that are to be transmitted by the base station. The scheduling buffer 558 is configured to store data packets that are scheduled for transmission by the base station based on parameters determined by the scheduling processor 560.
In some implementations, the scheduling processor 560 fetches data packets from the input buffer 552 and stores them in the scheduling buffer 558 for transmission. The scheduling processor recognizes the packets that have been pre-processed by the base station 506 to include header and/or encapsulation information for scheduling by the scheduling processor 560. For example, packets that are ready for scheduling by the scheduling processor 560 may include a PDCP header such that the scheduling processor 560 may recognize and schedule these packets for transmission.
In some implementations, the packet inspection processor 554 is configured to perform a packet inspection on each data packet that is buffered in the input buffer 552 prior to scheduling of the data packet for transmission. Packets may be inspected prior to being stored in the input buffer 552, or after storage in the input buffer 552. The packet inspection processor 554 may determine, for example, the application type of the data packet. An application type may correspond to, for example, audio, video, email, IM, or the like. The application type may also be specific to a particular provider of the data, for example, different types of IM applications. Based on the determined application type, the pre-scheduling processor 556 may determine a delay tolerance of the data packet. For example, the pre-scheduling processor 556 may assign a buffer timer (Tb) to the data packet based on the remaining time in its delay budget which is based on, for example, a look-up of settings associated with the application type that are stored in the base station memory 550.
The pre-scheduling processor 556 may also receive information indicative of the channel condition of a communication session with the user equipment 504. For example, the pre-scheduling processor 504 may receive Channel Quality Index (CQI) information which is continuously received and maintained by Layer 2 in the base station. Layer 2 may also convert the received CQI into a filtered signal to noise plus interference ratio (SINR) and provide the pre-scheduling processor 556 this information. If the CQI or SINR is below a predetermined threshold value (e.g., below −3 dB, 0 dB, or 3 dB), the pre-scheduling processor 556 may determine that the user equipment 504 is in a poor RF reception area, and in-turn may utilize the delay budget information associated with the data packet based on the application type of the data packet in order to delay pre-processing of the data packet. For example, the pre-scheduling processor 556 may delay application of the PDCP header to the data packet in the input buffer 552 when it is determined that the user equipment 504 is in a poor RF reception area. For data packets that are determined to be associated with delay intolerant applications, the pre-scheduling processor 556 does not delay the scheduling of the data packet for transmission.
The packet scheduling processor 560 schedules data packets for transmission that are stored in the scheduling buffer 558. The packet scheduling processor 560 may also take into account the results of the packet inspection performed by the packet inspection processor 554 in scheduling of data packets. For example, in some implementations, the packet inspection processor 554 may determine a priority of the data packet and/or a data loss sensitivity of the data packet, and may mark the packet for scheduling by the scheduling processor 560 accordingly. For example, different Modulation Coding Scheme (MCS) indices may be utilized, in order to include additional redundancies and a lower order modulation for data packets that are, according to the settings of the base station, deemed more important and/or sensitive than other data packets. For example, an MCS index having higher reliability may be utilized for synchronization and/or other state transition/communication setup data packets than for data transfer packets in a communication session. In the case of a delay intolerant application, the packet scheduling processor may utilize a MCS index having higher reliability in scheduling the data packets for transmission to a user equipment 504 in a poor RF reception area.
In some implementations, the packet may be marked by appending metadata to the packet or by modifying an existing field in one or more headers of the data packet. In some implementations, the priority and/or delay sensitivity may be communicated to the scheduling processor 560 based on an association of the priority and/or delay sensitivity with data identifying the data packet or application type of the data packet.
For example, if the data packet is carrying delay sensitive information for the user's application such as a response to a Domain Name System (DNS) query, the packet inspection processor 554 may set the priority value for the packet in such a way to indicate to the packet scheduling processor 560 that the packet is to be transmitted ahead of other packets in the buffer that are not delay sensitive, e.g. packets corresponding to an email message. As another example, streaming VoIP application packet (e.g., internet radio) generally has lower loss and delay sensitivity relative to a conversational VoIP packet (e.g., Skype®). In this example, the packet inspection processor 554 may determine and indicate that the packet requires transmission with a default priority level and higher Modulation Coding Scheme (MCS) index. Various combinations of priority value, MCS, or other scheduling parameters may be provisioned based on pre-set or dynamic settings stored in the base station memory 550 that correlate scheduling settings with packet inspection results
In some implementations, the packet inspection may be one of a shallow packet inspection (SPI) and/or a deep packet inspection (DPI). A shallow packet inspection may be performed by inspecting one or more headers of the data packet to determine some information associated with the data packet. For example, the shallow packet inspection may inspect the IP header of the data packet in order to determine the source IP address of the data packet. Based on the shallow packet inspection, in some implementations, the packet inspection processor 460 may perform a deep packet inspection, for example by examining other layers of the data packet. For example, the deep packet inspection may include an inspection of one or more of layers 1-7 of an open systems interconnect (OSI) model data packet. In some implementations, the packet inspection processor 554 may inspect the payload of a data packet to determine how the data packet should be processed by the pre-scheduling processor 556 and the packet scheduling processor 560. In some implementations, the packet inspection processor 554 may be configured to perform shallow packet inspection for all incoming and outgoing packets, while performing deep packet inspection on a subset of packets based on the settings that are stored in or provided to the base station.
In some implementations, the packet inspection processor 554 may determine the state of the application to which the data packets being communicated correspond. For example, by examining a data packet header (e.g., in Layer 7)), the packet inspection processor 554 may determine if the application is in a setup/establishment state or a connected/streaming state for communication. As one example, for a TCP communication session, TCP synchronization packets are exchanged during a TCP connection establishment state prior to TCP data transfer. The packet inspection processor 460 may determine that a data packet corresponds to a TCP synchronization packet that is communicated during the TCP establishment state, and in response, the pre-scheduling processor 556 may determine that the data packet is delay intolerant and process the data packet accordingly. Additionally or alternatively, the packet inspection processor 554 may mark the TCP establishment data packet for higher priority scheduling and/or higher reliability MCS coding relative to a data transfer packet. As a result, data packets including state transition information may be scheduled and communicated accordingly, thereby reducing time required to transition a communication session from an establishment state to a data transfer state (congestion avoidance state for TCP).
The packet inspection processor 554 communicates the detected application type and/or other information (e.g., application state) that is derived from the data packet to the packet scheduling processor 560 and the pre-scheduling processor 556. The packet scheduling processor 560 may assign radio resource blocks based on the channel conditions of the communication link with the user equipment and/or the core network. The packet inspection processor 560 may take into account the application type, the size of the file associated with the data packet, the provider of the content, the user device type or profile information associated with the user to make inference for treatment by the packet scheduling processor 560. The packet scheduling processor 560 may take into account the quality of service (QoS) requirements for the data packet, a Channel Quality Indication (CQI) determined by the base station 506, a buffer status report (BSR) of the UE buffer, a power headroom report (PHR) from the UE, Channel State Information (CSI), Up Link Scheduling (ULS) data, and/or the indication provided by the packet inspection processor 554 to perform application aware scheduling.
With returned reference to FIGS. 2 and 3, the packet inspection processor 554 may correspond to a function that is part of layer 3 functions in the base station 106, 306. In some implementations, the packet inspection processor 554 may also be provided on a separate functional layer from the functional layers described with reference to FIGS. 2 and 3. The packet inspection processor 554 may be configured to communicate and coordinate with other functions performed by the base station 506. For example, the packet inspection processor 554 may coordinate with the radio resource management (RRM) functions described above with reference to FIG. 2.
In some implementations, the packet inspection processor 554 may interact with Radio Resource Management (RRM) of the base station to gauge traffic load on the base station. Based on the traffic load, the packet inspection processor 554 may modify the determinations (e.g., priority, MCS, or the like) for packet scheduling. For example, during heavy load conditions, the packet inspection processor 554 may indicate that a packet is not to be prioritized if it corresponds to a given set of applications.
In some implementations, the packet inspection processor 554 may utilize the statistics and data collection module in the base station to gather application specific Key Performance Indicators (KPIs), including, for example, indicators for accessibility, retainability, integrity, availability, and/or mobility.
In some implementations, the pre-scheduling processor 556 may be provided in layer 3 of the base station as sown in FIGS. 2 and 3. As discussed above, the pre-scheduling processor 556 may be responsible for determining when a PDCP header is to be applied to the data packet for further processing by the base station 506.
In some implementations, the packet scheduling processor 560 may be provided in layer 2 of the base station as shown in FIGS. 2 and 3. In those implementations in which functions of layer 2 are subdivided between the iBBU 306 and RRHs 302, the packet scheduling processor 560 may be implemented as part of the layer 2 functions that reside with the iRRH 302. The packet scheduling processor 560 may also be provided on a separate functional layer from the functional layers described with reference to FIGS. 2 and 3. The packet scheduling processor 560 may be configured to communicate and coordinate with other functions performed by the base station 406. In some implementations, the packet scheduling processor 560 may coordinate with the MAC layer, and in particular the hybrid automatic repeat request (HARQ) manager of the MAC layer, as well as with a physical layer of the base station. For example, the packet scheduling processor 560 may interact with the physical (PHY) layer to derive channel estimations before selecting a modulation and coding scheme (MCS) for a given resource block which will carry part of the data related to a given application. In some implementations, the packet scheduling processor 560 selects the MCS for a particular data packet or set of data packets based on the information it receives from all other layers in the base station functional framework, including the PHY layer.
An example of the flow of data though the base station and processing of data packets will be described in conjunction with FIG. 6. FIG. 6 illustrates another example of a base station for coordinating communication between a user equipment and an application server according to some implementations. Like reference numerals in FIG. 6 correspond to like elements as described in FIG. 5. FIG. 6 also illustrates various functional layers of the base station, include layer 2 PDCP 604A, layer 2 RLC 604B, layer 2 MAC 604C, and layer 1 PHY 602 as described above, for example, with reference to FIG. 2. As shown in FIG. 6, the input buffer 552 stores data packets that have been indicated as having an extended delay budget or a normal delay budget by the pre-scheduling processor 556. This indication is based on an inspection of the data packets by the packet inspection processor (DPI/SPI) 554. In the example shown in FIG. 6, the extended delay budget data packets are delayed with respect to the normal delay budget data packets, such that for every three normal delay budget data packets, a single extended delay budget data packet is moved from the input buffer to the scheduling buffer. Other examples of delay, for example, based on delay buffer timers, may also be utilized in order to delay the application of the PDCP header to the extended delay budget data packets in the input buffer such that they are not recognized and moved to the scheduling buffer by the packet scheduling processor 560.
In some implementations, channel condition determinations may be based on HARQ data that is transferred from the MAC layer to the packet scheduling processor 560 and the pre-scheduling processor 556. For example, where multiple repeat transmission requests are initiated in a communication session with a user equipment, the pre-scheduling processor 556 may determine that the user equipment is in a poor RF reception area and process data packets based on their delay tolerance.
FIG. 7 is a flowchart of a method 700 of coordinating communication between a user equipment and an application server according to some implementations. The method 700 may be performed by a base station, for example, as described above with reference to FIGS. 5 and 6. As shown in FIG. 7, at block 702 a data packet is received at the base station and stored at the base station's input buffer. At block 704, the base station determines the channel condition of a communication session with a user equipment associated with the destination of the data packet. At decision block 706, the determined channel condition is compared with a threshold value, for example, to determine whether the user equipment is in a good RF reception area or a poor RF reception area. If the channel condition is less than the threshold value, the data packet is inspected to determine a delay tolerance of the data packet as shown in block 708. For example different delay tolerances may be assigned to different application types, and the delay tolerances may be determined based on a determination of the application type of the data packet through packet inspection. If the channel condition is greater than the threshold value (e.g., the user equipment is in a relatively good RF reception area), the data packet is moved to a scheduling buffer as shown in block 710.
When the channel condition is below the threshold, a delay budget (e.g., time period corresponding to a maximum amount of delay) is utilized to determine when the data packet should be moved from the input buffer to the scheduling buffer. As shown in FIG. 7, at decision block 712, it is determined whether the application is delay tolerant or intolerant. If the data packet is associated with a delay tolerant application (e.g., an email application), then the data packet is moved to the scheduling buffer based on the determined delay budget of the application as shown in block 714. If the channel conditions change such that the user equipment transitions to a good RF reception area while the data packet is being delayed based on the determined delay budget of the data packet, the data packet is moved to the scheduling buffer without reference to any extended delay budget that is applied based on the application type of the data packet.
If the application is delay intolerant, then the application is moved to the scheduling buffer in due course as shown in block 710. For example, the data packet for an intolerant application is moved to the scheduling buffer, based on, for example, the state of the scheduling buffer and currently load of other data packets that are to be moved to the scheduling buffer. Movement of the data packet from the input buffer to the scheduling buffer may be performed based on tagging or encapsulating the data packet with additional data, for example, such as by applying a PDCP header to the data packet. For data packets associated with delay tolerant applications that are to be transmitted to user devices in a poor RF reception area, the application of the tag or encapsulation of the data packet is delayed based on the delay tolerance of the application. As shown in block 716, the data packets that are in the scheduling buffer are scheduled for transmission.
Various aspects of embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure one skilled in the art should appreciate that an aspect described herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented and/or such a method may be practiced using other structure and/or functionality in addition to or other than one or more of the aspects set forth herein.
The techniques described herein may be used for various wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms “networks” and “systems” are often used interchangeably. A CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc.
A TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). An OFDMA network may implement a radio technology such as Long Term Evolution (LTE), Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, IEEE 802.22, Flash-OFDMA, etc. UTRA, E-UTRA, and GSM are part of Universal Mobile Telecommunication System (UMTS).
Single carrier frequency division multiple access (SC-FDMA), which utilizes single carrier modulation and frequency domain equalization is a technique. SC-FDMA has similar performance and essentially the same overall complexity as those of OFDMA system. SC-FDMA signal has lower peak-to-average power ratio (PAPR) because of its inherent single carrier structure. SC-FDMA has drawn great attention, especially in the uplink communications where lower PAPR greatly benefits the mobile terminal in terms of transmit power efficiency.
In some aspects the teachings herein may be employed in a network that includes macro scale coverage (e.g., a large area cellular network such as a 3G or 4G network, typically referred to as a macro cell network) and smaller scale coverage (e.g., a residence-based or building-based network environment). As an access terminal (AT) or user equipment (UE) moves through such a network, the access terminal may be served in certain locations by access nodes (ANs) that provide macro coverage while the access terminal may be served at other locations by access nodes that provide smaller scale coverage. In some aspects, the smaller coverage nodes may be used to provide incremental capacity growth, in-building coverage, and different services (e.g., for a more robust user experience). In the discussion herein, a node that provides coverage over a relatively large area may be referred to as a macro node. A node that provides coverage over a relatively small area (e.g., a residence) may be referred to as a femto node. A node that provides coverage over an area that is smaller than a macro area and larger than a femto area may be referred to as a pico node (e.g., providing coverage within a commercial building).
A cell associated with a macro node, a femto node, or a pico node may be referred to as a macro cell, a femto cell, or a pico cell, respectively. In some implementations, each cell may be further associated with (e.g., divided into) one or more sectors.
In various applications, other terminology may be used to reference a macro node, a femto node, or a pico node. For example, a macro node may be configured or referred to as an access node, base station, access point, eNodeB, macro cell, and so on. Also, a femto node may be configured or referred to as a Home NodeB (HNB), Home eNodeB (HeNB), access point base station, femto cell, and so on.
The teachings herein may be incorporated into (e.g., implemented within or performed by) a variety of apparatuses (e.g., nodes). In some aspects, a node (e.g., a wireless node) implemented in accordance with the teachings herein may comprise an access point or an access terminal.
For example, an access terminal may comprise, be implemented as, or known as user equipment, a subscriber station, a subscriber unit, a mobile station, a mobile, a mobile node, a remote station, a remote terminal, a user terminal, a user agent, a user device, or some other terminology. In some implementations an access terminal may comprise a cellular telephone, a cordless telephone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having wireless connection capability, or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or smart phone), a computer (e.g., a laptop), a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music device, a video device, or a satellite radio), a global positioning system device, or any other suitable device that is configured to communicate via a wireless medium.
An access point may comprise, be implemented as, or known as a NodeB, an eNodeB, a radio network controller (RNC), a base station (BS), a radio base station (RBS), a base station controller (BSC), a base transceiver station (BTS), a transceiver function (TF), a radio transceiver, a radio router, a basic service set (BSS), an extended service set (ESS), or some other similar terminology.
In some aspects a node (e.g., an access point) may comprise an access node for a communication system. Such an access node may provide, for example, connectivity for or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired or wireless communication link to the network. Accordingly, an access node may enable another node (e.g., an access terminal) to access a network or some other functionality. In addition, it should be appreciated that one or both of the nodes may be portable or, in some cases, relatively non-portable.
A wireless node may be capable of transmitting and/or receiving information in a non-wireless manner (e.g., via a wired connection). Thus, a receiver and a transmitter as discussed herein may include appropriate communication interface components (e.g., electrical or optical interface components) to communicate via a non-wireless medium.
A wireless node may communicate via one or more wireless communication links that are based on or otherwise support any suitable wireless communication technology. For example, in some aspects a wireless node may associate with a network. In some aspects the network may comprise a local area network or a wide area network. A wireless device may support or otherwise use one or more of a variety of wireless communication technologies, protocols, or standards such as those discussed herein (e.g., CDMA, TDMA, OFDM, OFDMA, WiMAX, Wi-Fi, and so on). Similarly, a wireless node may support or otherwise use one or more of a variety of corresponding modulation or multiplexing schemes. A wireless node may thus include appropriate components (e.g., air interfaces) to establish and communicate via one or more wireless communication links using the above or other wireless communication technologies. For example, a wireless node may comprise a wireless transceiver with associated transmitter and receiver components that may include various components (e.g., signal generators and signal processors) that facilitate communication over a wireless medium.
Any reference to an element herein using a designation such as “first,” “second,” and so forth does not generally limit the quantity or order of those elements. Rather, these designations may be used herein as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements may be employed there or that the first element must precede the second element in some manner.
Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.
Any of the various illustrative logical blocks, modules, processors, means, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source coding or some other technique), various forms of program or design code incorporating instructions (which may be referred to herein, for convenience, as “software” or a “software module), or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. In summary, it should be appreciated that a computer-readable medium may be implemented in any suitable computer-program product.
The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein and in connection with FIGS. 1A-D, and 2-6 may be implemented within or performed by an integrated circuit (IC). The IC may comprise a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute codes or instructions that reside within the IC, outside of the IC, or both. The logical blocks, modules, and circuits may include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. The functionality of the modules may be implemented in some other manner as taught herein. It is understood that any specific order or hierarchy of steps in any disclosed process is an example of a sample approach. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged while remaining within the scope of the present disclosure. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented.
The systems and methods disclosed herein can be embodied in various forms including, for example, a data processor, such as a computer that also includes a database, digital electronic circuitry, firmware, software, or in combinations of them. Moreover, the above-noted features and other aspects and principles of the present disclosed implementations can be implemented in various environments. Such environments and related applications can be specially constructed for performing the various processes and operations according to the disclosed implementations or they can include a general-purpose computer or computing platform selectively activated or reconfigured by code to provide the necessary functionality. The processes disclosed herein are not inherently related to any particular computer, network, architecture, environment, or other apparatus, and can be implemented by a suitable combination of hardware, software, and/or firmware.
As used herein, the term “user” can refer to any entity including a person or a computer.
Although ordinal numbers such as first, second, and the like can, in some situations, relate to an order; as used in this document ordinal numbers do not necessarily imply an order. For example, ordinal numbers can be merely used to distinguish one item from another. For example, to distinguish a first event from a second event, but need not imply any chronological ordering or a fixed reference system (such that a first event in one paragraph of the description can be different from a first event in another paragraph of the description).
The subject matter described herein can be implemented in a computing system that includes a back-end component, such as for example one or more data servers, or that includes a middleware component, such as for example one or more application servers, or that includes 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 implementation of the subject matter described herein, or any combination of such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, such as for example a communication network. Examples of communication networks include, but are not limited to, a local area network (“LAN”), a wide area network (“WAN”), and the Internet.
The computing system can include clients and servers. A client and server are generally, but not exclusively, remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.
The implementations set forth in the foregoing description do not represent all implementations consistent with the subject matter described herein. Instead, they are merely some examples consistent with aspects related to the described subject matter. Although a few variations have been described in detail above, other modifications or additions are possible. In particular, further features and/or variations can be provided in addition to those set forth herein. For example, the implementations described above can be directed to various combinations and sub-combinations of the disclosed features and/or combinations and sub-combinations of several further features disclosed above. In addition, the logic flows depicted in the accompanying figures and/or described herein do not necessarily require the particular order shown, or sequential order, to achieve desirable results. Other implementations can be within the scope of the following claims.

## Claims

1. A base station for transmitting data packets comprising:
a first buffer configured to store a data packet received by the base station;
a second buffer configured to store the data packet that is scheduled for transmission by the base station; and
a computer processor, operatively coupled to the first buffer and the second buffer, the computer processor being configured to:
inspect the data packet to determine an application type of the data packet, at least one of a priority, a loss sensitivity of the data packet, and a state of an application to which the data packet corresponds;
determine a delay tolerance associated with the data packet based on the determined application type, at least one of the priority and the loss sensitivity of the data packet, and the state of the application, wherein a buffer timer having a predetermined time limit is assigned based on the determined delay tolerance and based on a delay budget determined for the application type;
determine a channel condition of a communication session with a user device;
move the data packet from the first buffer to the second buffer based on the determined delay tolerance and the determined channel condition; and
transmit the data packet stored in the second buffer, wherein the data packet is transmitted upon expiration of the predetermined time limit and in accordance with a modulation coding scheme index determined based on the determined application type, the at least one of the priority and the loss sensitivity of the data packet, and the state of the application.

2. The base station of claim 1, wherein the computer processor is configured to:
determine a delay budget for the data packet;
schedule the data packet for transmission if the channel condition corresponds to a first channel condition; and
store the data packet for a time period that is equal to the delay budget prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.

3. The base station of claim 2, wherein the first channel condition corresponds to a channel condition in which the user device is located in a first RF reception area, and wherein the second channel condition corresponds to a condition in which the user device is located in a second RF reception area, and wherein the first RF reception area has greater RF reception than the second RF reception area.

4. The base station of claim 2, wherein the computer processor is configured to detect a change of the channel condition from the second channel condition to the first channel condition, and wherein the computer processor is configured to move the data packet to the second buffer upon detection of the change.

5. The base station of claim 1, wherein the computer processor is configured to detect that the data packet corresponds to a delay intolerant application or delay tolerant application, and wherein the computer processor is configured to schedule the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.

6. The base station of claim 5, wherein the computer processor is configured to transmit the data packets corresponding to delay intolerant applications with lower modulation than data packets corresponding to delay tolerant applications.

7. The base station of claim 5, wherein the computer processor is configured to transmit the data packets corresponding to delay intolerant applications with higher redundancy than data packets corresponding to delay tolerant applications.

8. The base station of claim 1, wherein the base station includes an evolved node (eNodeB) base station, wherein the first buffer includes an input buffer of the base station, and wherein the second buffer includes a scheduling buffer of the base station.

9. The base station of claim 1, wherein the computer processor is configured to inspect the data packet to determine at least one of an application type of the data packet and an application state corresponding to the data packet, and wherein the application state includes one of a data establishment state and a data transfer state.

10. The base station of claim 1, wherein the computer processor is configured to transmit the data packet to a remote radio head, and wherein the remote radio head includes a radio transmitter and a radio receiver.

11. The base station of claim 1, wherein the computer processor is configured to perform a shallow packet inspection of the data packet, and based on the shallow packet inspection, perform a deep packet inspection of the data packet.

12. The base station of claim 11, wherein the shallow packet inspection includes inspecting an IP header of the data packet, and wherein a deep packet inspection includes inspecting a payload of the data packet.

13. A method for transmitting data packets received by a base station, the method comprising:
storing a data packet received by the base station in a first buffer;
determining a channel condition of a communication session with a user device;
inspecting the data packet to determine an application type of the data packet, at least one of a priority, a loss sensitivity of the data packet, and a state of an application to which the data packet corresponds;
determining a delay tolerance associated with the data packet based on the determined application type, at least one of the priority and the loss sensitivity of the data packet, and the state of the application, wherein a buffer timer having a predetermined time limit is assigned based on the determined delay tolerance and based on a delay budget determined for the application type;
moving the data packet from the first buffer to a second buffer based on the determined delay tolerance and the determined channel condition; and
transmitting the data packet stored in the second buffer, wherein the data packet is transmitted upon expiration of the predetermined time limit and in accordance with a modulation coding scheme index determined based on the determined application type, the at least one of the priority and the loss sensitivity of the data packet, and the state of the application.

14. The method of claim 13, further comprising:
determining a delay budget for the data packet;
scheduling the data packet for transmission if the channel condition corresponds to a first channel condition; and
storing the data packet for a time period that is equal to the delay budget prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.

15. The method of claim 14, wherein the first channel condition corresponds to a channel condition in which the user device is located in a first RF reception area, and wherein the second channel condition corresponds to a condition in which the user device is located in a second RF reception area, and wherein the first RF reception area has greater RF reception than the second RF reception area.

16. The method of claim 14, comprising detecting a change of the channel condition from the second channel condition to the first channel condition, and wherein the moving the data packet to the second buffer upon detection of the change.

17. The method of claim 13, comprising detecting that the data packet corresponds to a delay intolerant application or delay tolerant application, and scheduling the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.

18. The method of claim 17, comprising transmitting data packets corresponding to delay intolerant applications with lower modulation than data packets corresponding to delay tolerant applications.

19. The method of claim 17, comprising transmitting data packets corresponding to delay intolerant applications with higher redundancy than data packets corresponding to delay tolerant applications.

20. The method of claim 13, wherein the base station includes an evolved node (eNodeB) base station, wherein the first buffer includes an input buffer of the base station, and wherein the second buffer includes a scheduling buffer of the base station.

21. The method of claim 13, comprising inspecting the data packet to determine at least one of an application type of the data packet and an application state corresponding to the data packet, and wherein the application state includes one of a data establishment state and a data transfer state.

22. The method of claim 13, comprising transmitting the data packet to a remote radio head, and wherein the remote radio head includes a radio transmitter and a radio receiver.

23. The method of claim 13, comprising performing a shallow packet inspection of the data packet, and based on the shallow packet inspection, performing a deep packet inspection of the data packet.

24. The method of claim 23, wherein the shallow packet inspection includes inspecting an IP header of the data packet, and wherein a deep packet inspection includes inspecting a payload of the data packet.

25. A non-transitory computer readable medium having stored thereon a computer program product having instructions configured to cause processing circuitry of a base station to:
store a data packet received by the base station in a first buffer;
inspect the data packet to determine an application type of the data packet, at least one of a priority, a loss sensitivity of the data packet, and a state of an application to which the data packet corresponds;
determine a delay tolerance associated with the data packet based on the determined application type, at least one of the priority and the loss sensitivity of the data packet, and the state of the application, wherein a buffer timer having a predetermined time limit is assigned based on the determined delay tolerance and based on a delay budget determined for the application type;
determine a channel condition of a communication session with a user device;
move the data packet from the first buffer to the second buffer based on the determined delay tolerance and the determined channel condition; and
transmit the data packet stored in the second buffer, wherein the data packet is transmitted upon expiration of the predetermined time limit and in accordance with a modulation coding scheme index determined based on the determined application type, the at least one of the priority and the loss sensitivity of the data packet, and the state of the application.

26. The non-transitory computer readable medium of claim 25, wherein the computer program product includes instructions configured to cause the processing circuitry to:
determine a delay budget for the data packet;
set a delay timer based on the determined delay budget;
schedule the data packet for transmission if the channel condition corresponds to a first channel condition; and
store the data packet for a time period that is equal to the delay timer prior to scheduling the data packet for transmission while the channel condition corresponds to a second channel condition.

27. The non-transitory computer readable medium of claim 26, wherein the first channel condition corresponds to a channel condition in which the user device is located in a first RF reception area, and wherein the second channel condition corresponds to a condition in which the user device is located in a second RF reception area, and wherein the first RF reception area has greater RF reception than the second RF reception area.

28. The non-transitory computer readable medium of claim 26, wherein the computer program product includes instructions configured to cause the processing circuitry to detect a change of the channel condition from the second channel condition to the first channel condition, and move the data packet to the second buffer upon detection of the change.

29. The non-transitory computer readable medium of claim 25, wherein the computer program product includes instructions configured to cause the processing circuitry to detect that the data packet corresponds to a delay intolerant application or delay tolerant application, and schedule the data packet utilizing a more reliable transmission protocol for data packets corresponding to delay intolerant applications than for data packets corresponding to delay tolerant applications.