Multipath Transmission for 6LoWPAN Networks
draft-pu-6lo-multipath-transmission-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Expired".
|
|
|---|---|---|---|
| Authors | Chenggen Pu , Yadong Wang , Heng Wang , 15023705316@163.com , Ping Wang | ||
| Last updated | 2017-09-07 | ||
| RFC stream | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | I-D Exists | |
| Telechat date | (None) | ||
| Responsible AD | (None) | ||
| Send notices to | (None) |
draft-pu-6lo-multipath-transmission-01
6lo C. Pu
Internet Draft Y. Wang
Intended status: Standards Track H. Wang
Expires: March 11, 2018 Y. Yang
P. Wang
Chongqing University of
Posts and Telecommunications
September 7, 2017
Multipath Transmission for 6LoWPAN Networks
draft-pu-6lo-multipath-transmission-01
Abstract
This document provides a multipath transmission method for 6LoWPAN
Networks, which can effectively offer the transmission redundancy of
packets. It is applicable for high-reliability networks,especially
for IPv6-based wireless industrial scenarios.
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), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
This Internet-Draft will expire on March 11, 2018.
Pu, et al. Expires March 11, 2018 [Page 1]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
Copyright Notice
Copyright (c) 2017 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. 6LoWPAN Multipath Header Format ............................. 3
3. Architecture ................................................ 3
4. Multipath Distribution ...................................... 4
5. Packet Replication and Elimination .......................... 6
6. Security Considerations ..................................... 7
7. IANA Considerations ......................................... 7
8. References .................................................. 7
8.1. Normative References ................................... 7
8.2. Informative References ................................. 8
Authors' Addresses ............................................. 9
1. Introduction
6LoWPAN has high popularity and applicability, and has more address
space that can realize the deployment of large-scale and high-
density wireless personal area network devices. However, due to the
low processing power, limited energy and poor communication
environment in 6LoWPAN, packets are prone to be lost during
transmission, which results in transmission failure. In order to
increase the communication reliability and improve the transmission
performance, it is significant to introduce multipath packet
transmission technology in 6LoWPAN. It is well known that RPL as a
routing protocol standardized by IETF, is an efficient distance
vector protocol for wireless sensor networks, which has designed a
series of new mechanisms [RFC6550], and is widely used in 6LoWPAN.
Aiming at the explicit demand for 6LoWPAN adopting multipath packet
transmission, this document proposes a multipath transmission method
based on RPL, which improves the success rate of packets
Pu, et al. Expires March 11, 2018 [Page 2]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
transmission in uplink networks and further enhances the
transmission reliability.
2. 6LoWPAN Multipath Header Format
6LoWPAN multipath header designed at the adaptation layer contains
the multipath header type field, the sequence number field of the
multipath package (SequenceNumber) and the path number field
(PathCount) [RFC4944], as depicted in Figure 1.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Multipath | Sequence Number | Path Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: 6LoWPAN Multipath Header Format
Field definitions are as follows.
Multipath: Headers of different types at the adaptation layer must
have a length of 8-bit header type field. The multipath field is
the header type field of 6LoWPAN Multipath Header that uses the
Dispatch Value Bit Pattern of 11101000.
Sequence Number: This field contains the unique sequence number
SequenceNumber of packets, and its length is 16 bits.
Path Number: This field includes the number of paths PathCount that
needs to be filled in the packet, and its length is 8 bit.
3. Architecture
The following figure 2 shows the architecture of the 6LoWPAN
protocol stack. In this architecture, the IP layer uses RPL to
realize the multipath transmission. Moreover, at the adaptation
layer, the multipath transmission entity is achieved by designing a
multipath header. The encapsulation of multipath packets and the
transmission of multipath packets can be implemented by using above
methods.
Pu, et al. Expires March 11, 2018 [Page 3]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
+---------------------------------------------------+
| COAP Application Layer XMPP |
|---------------------------------------------------|
| UDP Transport Layer |
|---------------------------------------------------|
| ----- --------------|
| |RPL| IP Layer | Multipath||
| ----- |Transmission||
| --------------|
|---------------------------------------------------|
| ------------------|
| Header Adaptation Layer | Multipath||
| Compression |Transport Entity||
| ------------------|
|---------------------------------------------------|
| CSMA/CA Mac Layer |
|---------------------------------------------------|
| Channel Detection Physical Layer |
+---------------------------------------------------+
Figure 2: 6LoWPAN Protocol Stack Architecture
Before the source node sends a message, it is necessary to determine
the number of paths P according to reliability requirements. Then we
need to assign one or more paths for each parent node at the IP
layer through the rank value. The rank value is calculated according
to the residual energy value and the hop value to the sink node from
the source node [RFC6551], [RFC6552]. The number of paths is
encapsulated into the multipath header of the message at the
adaptation layer before sending the message to the parent node.
Moreover, each intermediate routing node forwards the message
according to the above method until it reaches the sink node.
4. Multipath Distribution
If the required number of paths P is greater than the total number
of parent nodes N in the collection of RPL parent nodes, multiple
paths are assigned to each parent node according to the size
relation among the rank values of all parent nodes. The following
formula is used.
Pm = round (P/Rm/R) where R = 1/R1 + 1/R2 +...+ 1/Rn
Here, round() presents the rounding function, rounding for the
calculation result of (P/Rm/R). P is the total number of paths. Pm
shows the number of paths allocated for parent node m. Rm represents
Pu, et al. Expires March 11, 2018 [Page 4]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
the Rank value corresponding to the parent node m (m=1,2,...,n). The
above situation is shown as Figure 3.
+---------------------------------------------------+
| rank2=500 P2=1 |
| +------------>(R1)----> ..... |
| | |
| | |
| | /---->(R3)---->(R4)----> .....\ |
| |rank1=100 P1=5/ \ |
|(S) ---------->(R2).....--->(R5)--->(R6)---> ...(D)|
| |P=8 \ / |
| | \---->(R7)---->(R8)----> ...../ |
| | |
| |rank3=200 P3=2 /----> ..... |
| +---------------->(R9) |
| \----> ..... |
+---------------------------------------------------+
Figure 3: The Transmission Process of P>N
If the number of paths P is less than or equal to the total number
of parent nodes, P rank values are selected according to the rise
order of rank values, and one path is assigned to the parent node
corresponding to each rank value, as shown in Figure 4.
+---------------------------------------------------+
| rank2=500 P2=1 |
| +---------------->(R1)---->(R2)---->(R3)......... |
| | | |
| | rank1=100 P1=1 | |
| | /-------------->(R4)---->(R5)---->(R6)......\ | |
| |/ \| |
|(S)P=3 (D)|
| .\rank3=200 P3=1 /. |
| . \-------------->(R7)---->(R8)---->(R9)....../ . |
| . . |
| . rank4=600 P4=0 . |
| ..................(10)....(R11)....(R12)......... |
| |
+---------------------------------------------------+
Figure 4: The Transmission Process of P<=N
Pu, et al. Expires March 11, 2018 [Page 5]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
5. Packet Replication and Elimination
The process of packet multipath transmission also includes packet
replication and elimination. A detailed description is given as
following five steps.
1) When the multipath transport entity of the adaptation layer
receives the packet from the upper layer of the protocol stack, it
first determines the total number of paths P to transmit the packet
according to the reliability requirements of the packet. When P is
less than or equal to 1, indicating that the packet does not need to
use multipath transmission, then the packet can be forwarded
directly.
2) When the total number of paths P is larger than 1, the multipath
packet allocation method is used to allocate the number of the
replicated packets PathCount that needs to be forwarded by each
parent node in the collection of RPL parent nodes [I-D.ietf-detnet-
architecture], [I-D.ietf-detnet-problem-statement].
3) For the parent node that PathCount is greater than or equal to
1, the multipath transport entity replicates the packet and adds the
multipath header at the adaptation layer, and then sends the packet
to the parent node. In this case, the packet sequence number
SequenceNumber of the multipath header in all replicated packets
must be consistent and it can be accumulated when the next new
packet is sent. The path number field is filled with the
corresponding number of copies PathCount. For the parent node whose
number of copies PathCount is less than 1, the source node does not
send the packet.
4) After the intermediate routing node receives the packet
containing the multipath header, it judges whether the number of
paths PathCount in the multipath header is equal to 1. If PathCount
is equal to 1, the intermediate node sends the packet directly with
the value of each field in the multipath header constant. If
PathCount is greater than 1, the node has to replicate PathCount
copies of the packet and distributes them to multiple paths.
Repeating step 2 and 3, and in step 2, P is equal to PathCount. In
step 3, the new multipath header is not added, the SequenceNumber of
the packet is unchanged, and the path number field is filled with
the new corresponding number of copies.
5) When a destination node receives a packet containing the
multipath header, it can distinguish whether the packet has been
received according to the source address and the packet sequence
Pu, et al. Expires March 11, 2018 [Page 6]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
number in the multipath header. If the destination node has not
received the packet before, the node forwards the packet to its
upper layer protocol directly. Otherwise, the node discards the
packet [I-D.ietf-detnet-architecture], [I-D.ietf-detnet-problem-
statement].
6. Security Considerations
This document does not add any new security considerations beyond
what the referenced technologies already have.
7. IANA Considerations
This document creates an IANA registry for 6LoWPAN Multipath Header
Type, and assigns the following dispatch type values:
11101000: for 6LoWPAN Multipath Header Type.
8. References
8.1. Normative References
[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, JP.,
and R. Alexander, "RPL: IPv6 Routing Protocol for Low-Power
and Lossy Networks", RFC 6550, March 2012,
<http://www.rfc-editor.org/info/rfc6550>.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
"Transmission of IPv6 Packets over IEEE 802.15.4 Networks",
RFC 4944, September 2007,
<http://www.rfc-editor.org/info/rfc4944>.
[RFC6551] Vasseur, JP., Ed., Kim, M., Ed., Pister, K., Dejean, N., and
D. Barthel, "Routing Metrics Used for Path Calculation in
Low-Power and Lossy Networks", RFC 6551, March 2012,
<http://www.rfc-editor.org/info/rfc6551>.
[RFC6552] Thubert, P., Ed., "Objective Function Zero for the Routing
Protocol for Low-Power and Lossy Networks (RPL)", RFC 6552,
March 2012, <http://www.rfc-editor.org/info/rfc6552>.
Pu, et al. Expires March 11, 2018 [Page 7]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
8.2. Informative References
[I-D.ietf-detnet-architecture]
Finn, N. and P. Thubert, "Deterministic Networking
Architecture", draft-ietf-detnet-architecture-03 (work in
progress), August 2017.
[I-D.ietf-detnet-problem-statement]
Finn, N. and P. Thubert, "Deterministic Networking Problem
Statement", draft-ietf-detnet-problem-statement-01 (work in
progress), September 2016.
Pu, et al. Expires March 11, 2018 [Page 8]
Internet-Draft Multipath Transmission for 6LoWPAN September 2017
Authors' Addresses
Chenggen Pu
Chongqing University of Posts and Telecommunications
2 Chongwen Road
Chongqing, 400065
China
Phone: (86)-23-6246-1061
Email: mentospcg@163.com
Yadong Wang
Chongqing University of Posts and Telecommunications
2 Chongwen Road
Chongqing, 400065
China
Phone: (86)-23-6246-1061
Email: 13618266302@163.com
Heng Wang
Chongqing University of Posts and Telecommunications
2 Chongwen Road
Chongqing, 400065
China
Phone: (86)-23-6248-7845
Email: wangheng@cqupt.edu.cn
Yi Yang
Chongqing University of Posts and Telecommunications
2 Chongwen Road
Chongqing, 400065
China
Phone: (86)-23-6246-1061
Email: 15023705316@163.com
Ping Wang
Chongqing University of Posts and Telecommunications
2 Chongwen Road
Chongqing, 400065
China
Phone: (86)-23-6246-1061
Email: wangping@cqupt.edu.cn
Pu, et al. Expires March 11, 2018 [Page 9]