Internet Research Task Force Hyeonjoon Jang Internet-Draft KAIST Intended status: Informational Expires: March 15, 2021 October 2020 The Device-to-Device Multi-hop Capability Based On Heterogenous Link Chaining draft-jang-iot-d2dlc-00 Abstract Recently, D2D communication is drawing attention as a technology capable of reducing an excessive load on a network infrastructure and increasing network coverage. When using heterogeneous wireless communication technologies such as WiFi and Bluetooth, which are basically provided to user terminals such as smartphones, the connectivity of D2D communication can be further strengthened. In this paper, we propose a multi-hop communication technique using heterogeneous wireless communication technologies. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on March 15, 2021. Jang Expires March 15, 2021 [Page 1] Internet-Draft D2D Heterogenous Link Stitching October 2020 Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . .. . . . . . 2 2. Heterogeneous Link Stitching. . . . . . . . . . . . . . . . . . 3 2.1 Discovering the neighboring nodes and end-to-end routes. . . . . 3 2.2 End-to-end TCP connection. . . . . . . . . . . . . . . . . . . . 3 3. IANA Considerations . . . . . . .. . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. References . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5.1. Normative References . . . . . . . . . . . . . . . . . . . . . 5 5.2. Informative References . . . . . .. . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction As the amount of mobile traffic generated by user terminals such as smartphones, which are widely used in recent years, is rapidly increasing, a direct communication between terminals (D2D) technology is attracting attention as a technology for preventing excessive load on the network infrastructure. In particular, most user terminals such as smartphones are basically equipped with various wireless communication interfaces such as WiFi and Bluetooth as well as cellular interfaces. In an environment in which various wireless communication technologies are mixed, a multi-hop communication technology composed of heterogeneous links can provide more opportunities for connection between user terminals. In fact, it is known that the use of D2D communication services such as OpenGarden can increase the message delivery rate up to 80% in dense crowd environments such as movie theaters and concerts and emergency situations. When implementing multi-hop networking technologies in the application layer, it has the advantage of supporting interworking between wireless communication technologies that are rapidly developing with the advent of the Internet of Things era without modifying the operating system. Therefore, in this document, we propose a heterogeneous multi-hop networking technique in the application layer and discuss considerations. Jang Expires March 15, 2021 [Page 2] Internet-Draft D2D Heterogenous Link Stitching October 2020 2. Heterogenous Link Stitching A brief description of the multi-hop networking technology in the application layer proposed in this document is shown in Figure 1. The agent application shown in Figure 1 is installed on nodes A, B, and C to perform multi-hop communication consisting of WiFi and Bluetooth links. In order to allow nodes A and C to send and receive HTTP data through a multi-hop path composed of heterogeneous links, the agent application is capable of : 1) discovering of neighboring nodes using heterogeneous communication technology and end-to-end routes between them 2) providing end-to-end TCP connections. 2.1 Discovering the neighboring nodes and end-to-end routes As shown in Figure 1, suppose that nodes A and B have connectivity through WiFi using WiFi-Direct technology and Bluetooth technology, and nodes B and C have connectivity through Bluetooth. In a given environment , agents installed in each node broadcast a HELLO message through all communication methods that exist in each terminal. Through the HELLO message, each terminal knows the address of a neighboring nodes connected via WiFi and Bluetooth. After the neighboring terminal is searched, the agent of A sends out a route search message (e.g. RREQ message) through all communication interfaces of A in order to find a route from terminal A to C. The RREQ message arriving at the agent of B through the WiFi connection between A and B is delivered to C through the Bluetooth interface of B, and through this, the multi-hop path consisting of WiFi and Bluetooth from A to C is searched. The agent of each terminal maintains the destination address and nexthop address found in this way. +-------------------+ +------------------+ +--------------------+ |+------+ +------+| | +------+| |+------+ +---------+| ||client|-->| agent|| | +---+agent|| ||client<---+ agent || |+------+ +---|--+| | | +|-----+| |+------+ +-|-------+| +---------------V---+ +-------Λ---V------+ +-----------Λ--------+ +---------------|---+ +-------|+ +|------+ +-------+ +-|--------+ | TCP/IP stack| | |TCP/IP || ||Blue- | |TCP/IP | | | Blue- | +---------------V---+ +-------Λ+ ||tooth | +-------+ | | tooth | +---------------|---+ +-------|+ ||(RFC- | +-------+ | | (RFC- | | IEEE802.11 | | |802.11 || ||OMM) | |802.11 | | | OMM) | +---------------V---+ +-------Λ+ +V------+ +-------+ +-Λ--------+ | | | | +----->---------+ +------------------------+ +------------------------+ +--------------------------+ | B's IPaddr | C's IPaddr| | C's BTaddr | C's IPaddr | +------------------------+ +--------------------------+ Figure 1: Heterogeneous Multihop Link Stitching in Application Layer 2.2 End-to-end TCP Connection In order for the web browser application (client) of node A to communicate with the HTTP server of node C, the agent of each node was implemented as a local HTTP proxy. All HTTP packets are sent to the Jang Expires March 15, 2021 [Page 3] Internet-Draft D2D Heterogenous Link Stitching October 2020 operating system's TCP layer. As shown in the red line in Figure 1, the HTTP payload goes through the agent, and the nexthop is determined according to the destination information maintained by the agent, and it goes down to the corresponding transmission layer. For example, in Figure 1, a packet whose destination is C's IP address is encapsulated as an TCP/IP packet whose destination is B's IP address because the nexthop is B's WiFi interface. When it is delivered to B, and the agent of B forwards the original packet destined for C's IP address to the corresponding nexthop, C's Bluetooth interface(Which has C's BTaddr as its Bluetooth address). A:Client A:agent B:agent C:agent C:server | | | | | |<----------------->| | | | | TCP connected | | | | | | | | | | HTTP/TCP data | | | | |------------------>| | | | |<------------------| | | | | TCP ack | | | | | |<----------->| | | | | TCP connect | | | | | | | | | |<----------->| SYNC(->) & | | | | SYNC(->) & | RFCOMM ack(<-)| | | | TCP ack(<-) |<------------->| TCP connected | | | | |<-------------->| | | |<------------->| | | | | SYNC ack(<-) &| | | | | TCP ack(->) | | | |<----------->| | | | |SYNC ack(<-)&| | | | | TCP ack(->) | | | | | | | | Figure 2. End-to-end TCP connection Figure 2 shows the connection and data transmission between each node for HTTP communication between nodes A-C in the situation of Figure 1. The point to be considered in this situation is that node A's web browser (client) establishes a TCP connection with node A's agent (HTTP proxy) as shown in the figure, so the reliability of the connection to node C cannot be guaranteed. Therefore, each link must use reliable transmission protocols such as TCP and RFCOMM. 3. IANA Considerations There are no IANA considerations related to this document. Jang Expires March 15, 2021 [Page 4] Internet-Draft D2D Heterogenous Link Stitching October 2020 4. Security Considerations There are no security considerations related to this document. 5. References 5.1. Normative References 5.2. Informative References 6. Acknowledgements This work was supported by Institute for Information & communications Technology Promotion(IITP) grant funded by the Korea government(MSIT) (No.2015-0-00557, Resilient/Fault-Tolerant Autonomic Networking Based on Physicality, Relationship and Service Semantic of IoT Devices) Authors' Addresse Hyeonjoon Jang Electrical Engineering Department, Korea Advanced Institute of Science and Technology(KAIST) Daejeon, South Korea Phone: +82 (0)42 350 5473 Email: thefelix@kaist.ac.kr Jang Expires March 15, 2021 [Page 5]