Develop new MAC protocol for UWB with its simulation based on NS2

My plan at first: With the development of UWB, there are many MAC protocol for the UWB Networks, and they have different characters in different sides. First, some kinds of MAC protocol will be introduced, and through the analysis of them, we can find their advantages and disadvantages. At the same time, we will explore the problems in the design of MAC protocol. Certainly through the design of the physical layer, it is possible to make the UWB communication better, but it’s won’t be talked about for the reason that we just pay attention on the design of MAC protocol. After that, we will explore the key points in the design of the MAC protocol, such as now power control, privated MAC etc, which is important information for our design. In the end, the simulation based NS2 will taken to test our new MAC protocol, and we will modified the MAC protocol based on the results of the simulation on NS2. To test the MAC protocol repeatly, we can get the final design of MAC protocol.

In fact: But: Some information about uwb was collected. Some key-points during desining the uwb mac protocol were referred. But: I feel so sorry that I find that make a totally new mac protocol is too hard for me. So I just modified the 802.15.4 protocol to devolop a new mac in the end.

Introduction Some typical MAC protocols Ultra-wideband (aka UWB, ultra-wide band, ultraband, etc.) is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging. Most recent applications target sensor data collection, precision locating and tracking applications.1 Some typical MAC protocols DCC-MAC Multi-band IR-UWB MAC Sustained Link Networks(SLN), Burst-frame-based MAC UMAC etc.

DCC-MAC DCC-MAX protocol use PPM-TH-UWB as its physical layer, and it’s based on the Private MAC protocol and dynamic channel coding. Dynamic channel coding change the alternative interference management from through the channel code to through the controlling the transmission power. The private MAC is used to solve the problem that different signals compete for the same destination, and the solution doesn’t need a common channel which is different for the older one.

Multi-band IR-UWB MAC Multi-band IR-UWB MAC divide the available UWB band-width into multiple simultaneously usable bands. A multi-band approach can utilize the available spectrum well, and each transmitter sends longer pulses in one of the narrower bands. To make it more efficient, data transmissions are allowed to be contiguous.

The key points when designing the MAC protocol for the UWB That the optimal solution is achievable by a 0/Pmax strategy, and in the case of only peak power constraints (no average power constraint) any other strategy cannot by optimal. Allow low power transmissions to interfere, it causes a rate reduction, but it is less compared by the loss of the mutual exclusion. Rate control is necessary. It is referred that slotted sleeping is better than unslotted if occasional bursts must be supported, and unslotted sleeping is better than slotted if occasional maximum latency must be supported.

IEEE 802.15.4 IEEE 802.15.4a task group is dedicated to the development of a low grade industrial market wireless personal area network (PAN) standard, currently group Nanotron Technologies GmbH has been selected to design the broadband chirp spread spectrum (Chirp Spread Spectrum) physical layer physical layer technology as a benchmark standard. With last year’s 802.3 UWB (ultrawideband, UWB) PAN standard was sentenced to death, 802.15.4a PAN is considered the core of the potential of UWB applications. After the first round of voting, with 94% of the standard rate of adoption through the first round of voting proponents.

the super frame structure of 802.15.4

My simulation on NS2 First, I simulate the orignal demo given by Jianliang Zheng and Myung J. Leeon on the NS2.34 platform. video orignal_0 tcl orignal_0 process orignal_0

Process: Starting Simulation... --- startPANCoord [0] --- [0.000000](node 0) performing active channel scan [0.000000](node 0) scanning channel 11 channel.cc:sendUp - Calc highestAntennaZ_ and distCST_highestAntennaZ_ = 1.5, distCST_ = 35.9 SORTING LISTS ...DONE! [0.139520](node 0) scanning channel 12 [0.278720](node 0) scanning channel 13 [0.418560](node 0) begin to transmit beacons [0.419328](node 0) successfully started a new PAN (beacon enabled) [channel:11] [PAN_ID:0]--- startDevice [1] – [0.500000](node 1) performing active channel scan ... [0.500000](node 1) scanning channel 11 [0.764000](node 1) scanning channel 12 [1.026400](node 1) scanning channel 13 [1.288800](node 1) sending association request to [channel:11] [PAN_ID:0] [CoordAddr:0] ... [1.290848](node 1) sending association request command ...[1.292384](node 1) ack for association request command received--- startDevice [2] --- [1.500000](node 2) performing active channel scan ... [1.500000](node 2) scanning channel 11 [1.763680](node 2) scanning channel 12 [1.783904](node 1) sending data request command .. .[1.785184](node 1) ack for data request command received [1.787648](node 1) association response command received [1.787648](node 1) association successful (beacon enabled) [channel:11] [PAN_ID:0] [CoordAddr:0] [1.787648](node 1) begin to synchronize with the coordinator[2.028000](node 2) scanning channel 13

My simulation on NS2 Then, I find that if the start-time of the device, then the situation that some devices compete for the PAN to synchronize with the coordinator, which may lead to the result that some devices apply at first but wait more time. video orignal_1 tcl orignal_1 process orignal_1

Process: ….. [1.392448](node 2) sending association request command ... [1.394144](node 2) ack for association request command received [1.783584](node 1) sending data request command ... [1.784864](node 1) ack for data request command received [1.787328](node 1) association response command received [1.787328](node 1) association successful (beacon enabled) [channel:11] [PAN_ID:0] [CoordAddr:0][ 1.787328](node 1) begin to synchronize with the coordinator [1.885664](node 2) sending data request command ... [1.886944](node 2) ack for data request command received <!>[2.378464](node 2) association failed -> NO_DATA (beacon enabled) [channel:11] [PAN_ID:0] [CoordAddr:0]--- startDevice [3] --- [2.500000](node 3) performing active channel scan ... [2.500000](node 3) scanning channel 11 [2.762720](node 3) scanning channel 12 ….

The modification set a 0.5; set b 0.6; set c 2.6; set d 3.5; set e 4.5; set f 5.5; set waittime 0; //add waittime to mac, to remind the time the the device should wait before work set lasttime 0; //add lasttime to the coordinator, the coordinator should record the lasttime in order to make the choice when if… else…. ,also used to calculate the value of waittime if { $a < $lasttime } { //if ….else ….structure To avoid the competetion set waittime [expr $lasttime - $a] set lasttime [expr $lasttime + 1] $ns_ at [expr $a + $waittime] "$node_(1) sscs startDevice 1 0" } if { $a >= $lasttime } { $ns_ at $a "$node_(1) sscs startDevice 1 0" set lasttime [expr $a + 1] Repeat for the times the same with the number of the devices

Details: Addition: video modified_1 tcl modified_1 process modified_1 I just modify the demo and provide one possible way to change the mac, but I didn’t modify the mac in fact. Because after I compiling the new mac, the ns2 software can’t run any more…… - -b…… More efforts will be made on this problem if possible.

That’s all. Thank you ~