• The secret of success is learning how to use pain and pleasure instead of having pain and pleasure use you. If you do that, you're in control of your life. If you don't, life controls you.
      Tony Robbins

    • If you do what you've always done, you'll get what you've always gotten.
      Tony Robbins

  1. Address: Floor 3th, Information Technology Center of BASU University, Hamedan, Iran.

    Tel: +988138270182 & +988138268809         Email: info@wsnlab.org

    • Carry out the Wireless Sensor Network Simulation projects
    • Consulting the Wireless Sensor Network Projects
    • Implementation Hardware, Middle-ware and Software of WSN.

    for more information you can contact us: info@wsnlab.org

  2. Our Persian Forum ,

Fragmentation In 6lowpan Networks

Discussion in '6LowPAN Networks' started by Homaei, Nov 3, 2013.

  1. Homaei

    Homaei Administrator Staff Member

    If an entire payload data-gram fits within a single 802.15.4 frame, it is unfragmented and the LoWPAN encapsulation should not contain a fragmentation header. If the data-gram does not fit within a single IEEE 802.15.4, it shall be broken into link fragments.
    As the fragment offset can only express multiples of eight bytes, all link fragments except the last one must be multiples of eight bytes in length.
    The first link fragment header should follow the structure shown in the next figure:
    Fig1. First fragment
    The second and subsequent link fragments should conform the next format:
    Fig2. Subsequent fragment​

    • Datagram_size (11 bits): size of the entire IP packet before link-layer fragmentation. This value must be the same for all fragments.
    • Datagram_tag (16 bits): the sender should increment the data gram tag for successive fragmented datagrams. This value must be the same for all fragments of a payload.
    • Datagram_offset (8 bits): only in the second and subsequent fragments and in increments on 8 octets.

    The next figure is a graphical view of the different headers that can have a UDP packet sent over a 6LoWPAN network.


    Fig3. 6LoWPAN - UDP compressed

    Referenced by: http://www.wsnlab.org
    Author: Mohammah Hossein Homaei
    Wireless Sensor Networks Laboratory of Iran

Share This Page

Get our toolbar! Flag Counter