Simple AODV

1
Will IEEE 802.15.4 Make Ubiquitous Networking a
Reality? A discussion on a potential low power,
low bit rate standard
Jianliang Zheng and Myung J. Lee
2
Contents

• Why Another Standard?
• Applications
• An Overview of IEEE 802.15.4
• A Quantitative View of IEEE 802.15.4
• Conclusions
• An Animation Example
• Simulation Code Download

3
Why Another Standard?

• WLANs
• 802.11b (Wi-Fi)
• HiperLAN
• 802.11a/g
• WPANs
• 802.15.3a (UWB)
• 802.15.1 (Bluetooth)
• 802.15.4 (ZigBee)

20 250 Kbps
4
Why Another Standard? (cont.)

• Low-data-rate applications are closer to our
  daily lives than high data rate applications.
  But, so far, they have relatively been left in
  oblivion.
• Low-data-rate applications are expected to thrive
  and play an increasingly important role in our
  lives, thanks to
• the release of IEEE 802.15.4
• advances in other related fields
• embedded processors
• micro-electromechanical systems (MEMS)
• radio technologies

5
Why Another Standard? (cont.)
6
Why Another Standard? (cont.)
Low Rate Applications

IEEE 802.15.4
embedded processors
MEMS
radio technologies
7
Applications

• Automation and control
• Home
• Factory
• warehouse
• Monitoring
• Safety
• Health
• environments
• Situational awareness and precision asset
  location (PAL)
• military actions
• firefighter operations
• autonomous manifesting
• real-time tracking of inventory
• Entertainment
• learning games
• interactive toys

8
An Overview of IEEE 802.15.4

• Specifications for Low Rate Wireless Personal
  Area Networks (LR-WPAN)
• Basic features
• Low data rate
• Low power consumption
• Low cost
• Beacon enabled mode and non-beacon enabled mode
• Short transmission range Personal Operating
  Space (POS) of 10 meters or less.
• Topologies
• One-hop star
• Multi-hop peer-to-peer topology
• Addressing modes
• 64-bit IEEE address
• 16-bit logical address

9
An Overview of IEEE 802.15.4 (cont.)

• Bandwidth and data rate

10
An Overview of IEEE 802.15.4 (cont.)

• Supporting Simple Devices
• 14 PHY primitives 35 MAC primitives
• FFD RFD
• FFD is required to support all 49 primitives
• RFD is required to supports 38 primitives
• Different Data Transmission Methods
• Direct data transmission
• Indirect data transmission (data polling)
• GTS data transmission

11
An Overview of IEEE 802.15.4 (cont.)

• Low Power Consumption
• Beacon mode and superframe structure
• Indirect data transmission
• BatteryLifeExtension option
• Small backoff period in CSMA-CA
• Secure Data Transfer
• Three levels
• None security if security is not an important
  factor or the upper layer already provides
  sufficient security protection
• Access control list (ACL) prevent unauthorized
  devices from accessing its data.
• Data encryption using Advanced Encryption
  Standard (AES)

12
An Overview of IEEE 802.15.4 (cont.)

• Beacon Mode and Superframe Structure

13
An Overview of IEEE 802.15.4 (cont.)

• Self-Configuration and Orphaning

• A tree can be automatically formed through MAC
  association function.
• A 16-bit short address is assigned to each device
  during association.
• In beacon enabled mode, a device can track
  beacons from its parent for
• Synchronization
• Failure (orphaning) detection

14
A Quantitative View of IEEE 802.15.4

• NS2 Simulator

Wireless Scenario Definition
Upper Layers

• CSMA-CA
• Beacon and Sync.
• Assoc. and Disassoc.
• Tree Formation
• Diret. and Indirect. Tx
• Filtering
• Error Models
• Enhanced Nam Anima.

Routing
802.2 LLC

• ED
• CCA
• LQD
• Filtering
• Multiple Channel

SSCS
802.15.4 MAC
802.15.4 PHY
NS2
15
A Quantitative View of IEEE 802.15.4 (cont.)

• NS2 Simulator Functionality
• Pure CSMA-CA and Slotted CSMA-CA
• Legacy application support (802.11b compatible)
• Star and Peer-to-Peer topologies
• Beacon enabled and non-beacon enabled modes
• Beacon tracking and synchronization
• Association and Disassociation
• Peer-to-Peer Tree and Cluster Tree Formation
• Direct and Indirect (data polling and extraction)
  transmissions
• Energy Detection (ED)
• Clear Channel Assessment (CCA)
• Link Quality Detection (LQD)
• Multiple channel support
• Channel Scan (ED/Active/Passive/Orphan)
• Filtering (channel, beacon, duplication,
  interference, etc.)
• Simulation Tracing
• Deterministic Error Models (Node/Link)
• Enhanced Nam Animation

16
A Quantitative View of IEEE 802.15.4 (cont.)

• Packet Delivery Ratio Exp. Setup

• of nodes 101
• Area 80 x 80 m2
• Traffic type Poisson
• of traffic flows 6
• 64 ? 62
• 63 ? 61
• 99 ? 85
• 87? 97
• 88 ? 98
• 100 ? 86
• Duration 900 sec
• Nb. distance 7 m
• Tx range 9 m

17
A Quantitative View of IEEE 802.15.4 (cont.)

• Packet Delivery Ratio Results

18
A Quantitative View of IEEE 802.15.4 (cont.)

• Association Efficiency
• (Same experimental setup as before)

BC Beaconing Coordinator
19
A Quantitative View of IEEE 802.15.4 (cont.)

• Orphaning
• Experimental setup
• same topology as before
• all coordinators beaconing
• various beacon orders
• Experimental results
• Orphaning is more serious in smaller beacon
  orders (Table 2)
• In our experiments, the orphaning ratio is only
  2.11 in beacon order2, and there is no orphaning
  in beacon order 3 or above.
• In an environment with high rate of orphaning,
  the chance an orphaned device successfully
  recovers from all orphanings is very low, but the
  recovery rate of orphaning itself is not as bad
  (from 36.47 to 88.89).

20
A Quantitative View of IEEE 802.15.4 (cont.)

• Orphaning
• Experimental setup
• same topology as before
• all coordinators beaconing
• various beacon orders

21
A Quantitative View of IEEE 802.15.4 (cont.)

• Collision Experimental setup

• of nodes 7
• Area 50 x 50 m2
• Neighbor distance 10 m
• Traffic type Poisson
• of traffic flows 6
• (from devices to coord.)
• Traffic load 1 pkt/s
• Tx Range 15 m
• Duration 900 sec
• Beacon mode Enabled
• -- Beacon Order 0 8
• -- Superframe Order 0 8

PAN Coord
Device
22
A Quantitative View of IEEE 802.15.4 (cont.)

• Collision Results
• More collisions happen in lower beacon orders.
• Most collisions (from 70.3 to 99.7 in our
  experiments) happen between hidden terminals.
• Our experimental results show that the dropping
  of RTS/CTS in 802.15.4 is reasonable.
• The gain in packet delivery ratio is around 3.8
  (from 95.7 to 99.5) for a data rate of 1
  packet/s by using RTS/CTS, and only about 1 for
  data rates less than 0.2 packet/s.

23
Conclusions

• The number of applications that can benefit from
  802.15.4 is enormous.
• from home to office
• from industry to agriculture
• from civilian activities to military operations
• from indoors to outdoors
• By extending networks to cover all the simple
  devices and with the emerging of many interesting
  and wonderful applications, we are stepping
  closer to a ubiquitous networking era.

24
Conclusions (cont.)

• Many features of 802.15.4, such as
• using globally available ISM frequency bands
• power conservation
• self-configuration
• secure data transfer
• make it a unique technology having the promise
  to unify all those simple devices from different
  manufacturers and bring networks to the level of
  each person.
• However, while 802.15.4 provides a rather solid
  technique basis for many applications, its
  success in marketing still bears watching. The
  success of a new technology is not only
  determined by the technology itself, but many
  other factors as well.

25
An Animation Example 11 RN and 10 RN-
Scenario Snapshot
Traffic Flow 3 ? 18 CBR 9 ? 17 Poisson
Hop Count 3 ? 18 4 hops 9 ? 17 4 hops
26
Simulation Code Download

• Source Code Release (only available to ZigBee
  members)
• Contact ZigBee Network WG
• Binary Release
• http//www-ee.ccny.cuny.edu/zheng/pub