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<rfc category="info" docName="draft-liu-apn-edge-usecase-04" ipr="trust200902">
  <front>
    <title abbrev="Network Working Group">Use cases of Application-aware
    Networking (APN) in Edge Computing</title>

    <author fullname="Peng Liu" initials="P." surname="Liu">
      <organization>China Mobile</organization>

      <address>
        <postal>
          <street/>

          <city>Beijing</city>

          <code>100053</code>

          <country>China</country>
        </postal>

        <email>liupengyjy@chinamobile.com</email>
      </address>
    </author>

    <author fullname="Zongpeng Du" initials="Z." surname="Du">
      <organization>China Mobile</organization>

      <address>
        <postal>
          <street/>

          <city>Beijing</city>

          <code>100053</code>

          <country>China</country>
        </postal>

        <email>duzongpeng@chinamobile.com</email>
      </address>
    </author>

    <author fullname="Shuping Peng" initials="S." surname="Peng">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street/>

          <city>Beijing</city>

          <code>100053</code>

          <country>China</country>
        </postal>

        <email>pengshuping@huawei.com</email>
      </address>
    </author>

    <author fullname="Zhenbin Li" initials="Z." surname="Li">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street/>

          <city>Beijing</city>

          <code>100053</code>

          <country>China</country>
        </postal>

        <email>lizhenbin@huawei.com</email>
      </address>
    </author>

    <!---->

    <date day="13" month="December" year="2021"/>

    <area>Networking</area>

    <workgroup>Network Working Group</workgroup>

    <keyword>APN;edge computing</keyword>

    <abstract>
      <t>The ever-emerging new services are imposing more and more highly
      demanding requirements on the network. However, the current deployments
      could not fully accommodate those requirements due to limited
      capabilities. For example, it is difficult to utilize the traditional
      centralized deployment mode to meet the low-latency demand of some
      latency-sensitive applications. Moreover, the total amount of
      centralized service data is growing exponentially, which brings great
      pressure on the network bandwidth. There has been a clear trend that
      decentralized sites comprising of computing and storage resources are
      deployed at various locations to provide services. In particular, when
      the sites are deployed at the network edge, i.e. the Edge Computing, it
      can better handle the business needs of the users nearby, which provides
      the possibilities to provide differentiated network and computing
      services. In order to achieve the full benefits of the edge computing,
      it actually implies a precondition that the network should be aware of
      the applications' requirements in order to steer their traffic to the
      network paths that can satisfy their requirements. Application-aware
      networking (APN) aims to accommodate the edge services' needs, fully
      releasing the benefits of the edge computing.</t>

      <t>This document describes the various application scenarios in edge
      computing to which the APN can be beneficial, including augmented
      reality, cloud gaming and remote control, which empowers the video
      business, users interaction business and user-device interaction
      business. In those scenarios, APN can identify the specific requirements
      of edge computing applications on the network, process close to the
      users, provide SLA guaranteed network services such as low latency and
      high reliability.</t>
    </abstract>

    <note title="Requirements Language">
      <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
      "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
      document are to be interpreted as described in <xref
      target="RFC2119">RFC 2119</xref>.</t>
    </note>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <t>Edge computing is to deploy service sites near the user side to
      provide users with better network and computing services. The services
      of edge computing can not only be implemented in the edge data center,
      but also be integrated in the network equipment, which brings the
      possibility for the convergence of network and computing, and also puts
      forward the requirements for the technology combining of different
      industries. On the one hand, the demand of different applications for
      the network need to be exposed; on the other hand, the network needs to
      be aware of computing power and steers the traffic along the appropriate
      path towards the suitable sites.</t>

      <t>The existing network can only identify the application demands in a
      coarse granularity. When the application demand is high causing the
      heavy network load, it usually fails to guarantee the latency and
      reliability of the applications especially the mission-critical
      applications. Application-aware networking (APN) faciliates service
      provisioning in a fine granularity, and then either steer the
      corresponding traffic onto the appropriate network path (if exist) that
      can satisfy these requirements or establish an exclusive network path
      which wouldn't be influenced by other applications' traffic flow.</t>
    </section>

    <section title="Edge Computing and APN">
      <t>In a whole edge computing network, there are user terminal, edge
      gateway and edge data center. The edge gateway can be the UPF In 5G
      network. Edge data center is usually close to users and serves a limited
      group of users, the network and computing tasks performed by edge
      computing are more specific and customized. Both computing resources and
      network resources need to be able to provide fine-grained service
      guarantee. The goal of APN is to provide fine-grained network service,
      including latency, jitter, reliability and others, which can be well
      matched with edge computing.</t>

      <t>Appilication-aware networking includes the app-aware edge (APN-Edge),
      app-aware process head-end (APN-Head), app-aware process mid-point
      (APN-Midpoint) and app-aware process end-point (APN-Endpoint). A user's
      request is sent from the client, and then passes through all the nodes
      of the APN network to the server. The function of APN-Edge can be
      deployed in the edge gateway, so the request traffic of client can be
      distinguished by the edge gateway/APN-Edge and sent to the edge data
      center through the APN. In some cases, the reply of the edge data center
      will not return to the original client, and may be sent to another
      client through the APN. The APN network can use the exsiting
      technologies such as deterministic network, network slicing, SR policy,
      etc. which could coordinate well with the APN-Edge to garantee the
      network service by encapsulating the requirement information in the
      packets.</t>

      <figure align="center" title="Edge Computing and APN">
        <artwork type="ascii-art">
  +------+    +----------------+    +-------------+    +---------+ 
  |      |    | Edge Gateway/  |    |     APN     |    |  Edge   |
  |Client|&lt;--&gt;|                |&lt;--&gt;|             |&lt;--&gt;|  Data   | 
  |      |    | APN-Edge       |    |   Network   |    |  Center |   
  +------+    +----------------+    +-------------+    +---------+                                         
   </artwork>
      </figure>
    </section>

    <section title="Usage Scenarios of APN in edge computing">
      <t>This section presents several typical scenarios which require edge
      computing to interconnect and to co-ordinate with APN to meet the
      service requirements and ensure user experience.</t>

      <section title="Augmented Reality (AR) ">
        <section title="Use Case Description">
          <t>Augmented reality is a relatively new application that promotes
          the integration of real world information and virtual world
          information content. It includes several technologies, such as track
          registration, display, virtual object generation, interaction and
          merging.</t>
        </section>

        <section title="Augmented Reality Today">
          <t>AR gives users an immersive experience. It is widely used in the
          consumer industry presently, and may also be applied in industrial
          fields such as health care and education in the future. The general
          process of AR / VR is as follows:</t>

          <t>* Image acquisition equipment (such as camera) collects image or
          video information and sends it to data center.</t>

          <t>* Data center carries out identification, feature extraction and
          template rendering, and sends them to AR terminal.</t>

          <t>* The AR terminal plays the synthesized information.</t>

          <t>Considering the user experience, AR usually needs a high
          bandwidth of 100mbps due to multi-channel acquisition of image or
          video data, and a low end-to-end latency less than 60ms. With
          centralized deployment, the network transmission distance is too
          long, so the latency demand can't be met; the large volume of
          traffic load also imposes high challenge on the network
          bandwidth.</t>
        </section>

        <section title="Augmented Reality with Edge Computing and APN">
          <t>If the deployment mode of edge computing is adopted, the
          following functions can be realized:</t>

          <t>* The collected image or video information can be encoded/decode
          and compressed by the edge equipment to reduce the bandwidth
          requirements of data transmission.</t>

          <t>* The edge data center can process the collected image or video
          data nearby and send it to the AR terminal equipment, which reduces
          the distance of network transmission and greatly reduces the
          latency.</t>

          <t>Although edge computing can reduce the overall latency of
          services and reduce the demand for network bandwidth, it still needs
          differentiated network services to provide the ultimate guarantee
          for application with high SLA requirements. APN can achieve:</t>

          <t>* Edge device obtains and encapsulates AR application feature
          information and sends it to the headend node.</t>

          <t>* Headend node in the APN identifies the AR data flow and steers
          it into a specific transmission path according to the demanded
          bandwidth, latency and reliability.</t>

          <t>* Mid point in the APN forwards the data stream along the
          specific path.</t>

          <t>* End point in the APN receives AR data stream and forwards it
          either to Data Centre for processing or to the AR player for
          playing.</t>

          <t>In the whole process, because APN identifies the traffic of AR
          application, it can provide corresponding network services to
          provide customized high reliability, low latency and other SLA
          guarantee.</t>

          <figure align="center"
                  title="Augmented Reality with Edge Computing and APN">
            <artwork type="ascii-art">
  +------+  Camera                                               +------+ 
  |Source|                                                     -&gt;|  AR  |
  |data  |-\                                                  /  |Player|
  +------+|   +-----+   +-------+   +---------+   +-------+  /   +------+  
           \-&gt;|APN  |   |  APN  |   |  Edge   |   |  APN  |-/  
              |-    |--&gt;|       |--&gt;|  Data   |--&gt;|       |    
           /-&gt;|Edge |   |Network|   |  Center |   |Network|-\
  +------+ |  +-----+   +-------+   +---------+   +-------+  \   +------+
  |Source|-/                                                  \  |  AR  |
  |data  |                                                     -&gt;|Player| 
  +------+  Camera                                               +------+
 </artwork>
          </figure>
        </section>
      </section>

      <section title="Cloud Gaming">
        <section title="Use Case Description">
          <t>Cloud gaming is to deploy the game application in the data
          center, and realize the functions includes the logical process of
          game command control, as well as the tasks of game acceleration,
          video rendering and other tasks with high requirements for chips. In
          this way, the terminal is a video player. Users can get a good game
          experience without the support of high-end system and chips.</t>

          <t>Compared with the traditional game mode, there are several
          advantages of cloud game, such as no installation, no upgrade, no
          repair, quick to play and reduce the terminal cost, so it will have
          stronger promotion.</t>
        </section>

        <section title="Cloud Gaming Today">
          <t>The biggest feature of cloud games is that users interact with
          each other through the network. The general process is as
          follows:</t>

          <t>* The data center sends game video streaming information to the
          terminal, including game background picture, characters, etc.</t>

          <t>* The user makes corresponding operation instructions according
          to the received game video stream information and sends them to the
          data center.</t>

          <t>* The data center constantly updates the video stream and other
          data of the game according to the user's operation instructions.</t>

          <t>Game users usually pursue consumption experience. Currently, most
          users are willing to spend extra money in order to obtain better
          user experience. Generally speaking, the network latency of game is
          required to be less than 30ms. For competitive game, the latency
          will be required to be less than 10ms, because professional players
          usually can feel the millisecond level latency difference. With
          centralized deployment, the network transmission distance is too
          long, which is a huge challenge to the network load, so the latency
          demand can't be met; the large volume of traffic load also imposes
          high challenge on the network bandwidth.</t>
        </section>

        <section title="Cloud Gaming with Edge Computing and APN">
          <t>If the deployment of edge computing is adopted, the following
          functions can be realized with the deployment of edge data
          center:</t>

          <t>* The edge data center sends the game video stream information to
          the terminal, and receives the user's control instruction
          information for processing.</t>

          <t>* users can make corresponding operation instructions according
          to the received video stream information, and get quick
          response.</t>

          <t>Edge computing can reduce the latency of game data transmission
          as a whole, but it should be noted that cloud games usually have
          multiple players playing a game together, which requires the
          deterministic latency of multi-party network path, which needs to be
          realized with APN:</t>

          <t>* Multiple edge devices obtain and encapsulate cloud game
          application feature information and send it to the head end
          node.</t>

          <t>* Headend node in the APN identifies the data flow of cloud games
          (maybe the same game), and steers it into a specific transmission
          path according to its requirements for bandwidth, delay,
          reliability, etc., which needs to ensure that the latency of
          multi-user control instructions arriving at the edge data center is
          consistent.</t>

          <t>* Midpoint in the APN forwards game data stream according to the
          predetermined path.</t>

          <t>* The endpoint in the APN receives the cloud game data stream and
          steers it either to the data center for processing the users&rsquo;
          control instruction or to the user for playing.</t>

          <t>The whole process requires APN not only to identify the cloud
          game traffic and provide customized network forwarding services for
          it, but also to ensure the deterministic latency of multi-user in
          the same game and provide better game experience.</t>

          <figure align="center"
                  title="Cloud Gaming with Edge Computing and APN">
            <artwork type="ascii-art">   Client A
  +---------+                                                    
  |Game data|                                               
  +---------+-\   +----------+   +-----------+   +-----------+         
              |&lt;-&gt;|  APN-    |-A-|    APN    |-A-|           |      
                  |  Edge A  |   | Network A |   |           |
                  +----------+   +-----------+   | Edge Data |
                  +----------+   +-----------+   |   Center  | 
                  |  APN-    |   |    APN    |   |           |
              |&lt;-&gt;|  Edge B  |-B-| Network B |-B-|           |      
  +---------+-/   +----------+   +-----------+   +-----------+ 
  |Game data|                                                 
  +---------+                                                                                               
   Client B  </artwork>
          </figure>
        </section>
      </section>

      <section title="Remote control of industry">
        <section title="Use Case Description">
          <t>Industrial remote control refers to the remote control of field
          equipment in areas that are not convenient for manual field control,
          such as high-temperature and high-risk areas. In the past, signaling
          was usually transmitted through industrial private networks and
          protocols. With the development of industrial Internet, the industry
          also gradually has the demand of network interconnection. Its
          network tends to adopt L3 protocol and flat architecture, which
          makes it possible for cross distance remote control service.</t>
        </section>

        <section title="Remote control of industry Today">
          <t>In the process of remote control, workers constantly make control
          instructions according to the received image or video information of
          field equipment, which requires interaction between personnel and
          equipment through the network. Because the field environment that
          needs remote control is generally poor, it is also a challenge for
          the security of the operation equipment. If the latency is too large
          or the reliability is not enough, it may cause the operation
          failure, equipment damage and other serious consequences. Therefore,
          the remote control service requires low latency and high
          reliability. The general process of remote control is as
          follows:</t>

          <t>* Field equipment (such as camera) collects image or video
          information and sends it to data center.</t>

          <t>* The data center receives the field information of the equipment
          and sends it to the workers in the office.</t>

          <t>* Workers send control instructions and control equipment
          according to the received field information.</t>

          <t>Many industrial enterprises rent public cloud resources to
          construct their own data center, but the long distance of network
          transmission is not conducive to the timely transmission of image /
          video data stream, which will cause large latency and packet
          loss.</t>
        </section>

        <section title="Remote control of industry with Edge Computing and APN">
          <t>If the deployment mode of edge computing is adopted, and the data
          center and edge computing access equipment (such as gateway) are
          deployed in a location or enterprise park close to the business
          site, the following functions can be realized:</t>

          <t>* The collected image or video information can be encoded/
          decoded and compressed by edge access equipment to reduce the
          bandwidth requirements.</t>

          <t>* The control instruction information can be identified by the
          edge equipment, so as to provide exclusive network transmission
          service.</t>

          <t>* The forwarding path of image / video and control information is
          shortened, which can greatly reduce the latency.</t>

          <t>Although edge computing can reduce the overall delay of services
          and reduce the demand of network bandwidth, it still needs to
          achieve differentiated network services through APN to provide the
          ultimate network guarantee for the services with the highest network
          requirements.</t>

          <t>For users, APN can realize those functions.</t>

          <t>* Edge device obtains and encapsulates the image or video
          information of the remote field device, then sends it to the headend
          node.</t>

          <t>* Headend in the APN identifies the information and steers the
          flow into a specific transmission path according to its requirements
          for bandwidth, delay, reliability, etc..</t>

          <t>* Midpoint in the APN forwards along the specific path.</t>

          <t>* Endpoint receives image or video data stream of field equipment
          and forwards it to users.</t>

          <t>For field equipment, APN can realize those functions.</t>

          <t>* Edge device obtains and encapsulates the control instruction
          information and sends it to the head end node.</t>

          <t>* Headend in the APN identifies the control data flow and steers
          into a specific transmission path according to the demand for
          bandwidth, latency and reliability.</t>

          <t>* Midpoint in the APN forwards along the specific path.</t>

          <t>* Endpoint receives control information and forwards to the field
          equipment.</t>

          <t>In the whole process, APN identifies the traffic of remote
          control service, which can provide customized high reliability, low
          latency and other network guarantee.</t>

          <figure align="center"
                  title="Remote control of industry with Edge Computing and APN">
            <artwork type="ascii-art">      Worker
  +------------+                                                    
  |Control data|                                               
  +------------+-\   +----------+    +-----------+    +-----------+         
                 |&lt;-&gt;|  APN-    |-W-&gt;|    APN    |-W-&gt;|           |      
                     |  Edge A  |&lt;-C-| Network A |&lt;-C-|           |
                     +----------+    +-----------+    | Edge Data |
                     +----------+    +-----------+    |   Center  | 
                     |  APN-    |-C-&gt;|    APN    |-C-&gt;|           |
      Camera     |&lt;-&gt;|  Edge B  |&lt;-W-| Network B |&lt;-W-|           |      
  +------------+-/   +----------+    +-----------+    +-----------+ 
  | Video data |                                                 
  +------------+                                                                                               
  On-site Device </artwork>
          </figure>
        </section>
      </section>
    </section>

    <section title="Conclusion">
      <t>APN enables low latency and high reliability network services in
      various edge computing scenarios such as AR, cloud gaming, remote
      industrial control, etc.</t>
    </section>

    <section anchor="Security" title="Security Considerations">
      <t>TBD.</t>
    </section>

    <section anchor="IANA" title="IANA Considerations">
      <t>TBD.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include="reference.RFC.2119"?>

      <?rfc include="reference.I-D.li-apn-framework"?>

      <?rfc include="reference.I-D.li-apn-problem-statement-usecases"?>
    </references>
  </back>
</rfc>
