Smooth Video Handoff over Wireless Networks
description
Transcript of Smooth Video Handoff over Wireless Networks
Smooth Video Handoff over Wireless Networks
Yi Pan and Tatsuya Suda{ypan,suda}@ics.uci.eduSchool of Information and
Computer ScienceUniversity of California, Irvine
Outline Motivation Proposed scheme Simulation and demo Conclusion
Motivation Current handoff techniques:
Single mobile IP binding may cause packet loss during handoff
Switching data transmission path is dangerous for active sessions
Handoff causes transmission rate reduction Due to disparity of available bandwidth in different
cells, the transmission rate in the previous cell may not be proper to avoid congestion in the new cell
Network mobility support can not handle this problem
Motivation Multimedia applications need a
smooth handoff provides Reduced packet loss Continuous streaming Congestion avoidance in new cell Smooth adaptation of video quality to
various bandwidth
Our Proposal Use multiple paths to reach a single mobile
node Assign different mobile IP addresses (COAs) to
different paths reaching a single mobile node Exploit different amounts of bandwidth on
multiple paths to a single mobile node To reduce or prevent a packet loss due to hand
off To increase throughput for the mobile node
Basic Ideas Preventing a packet loss due to handoff
Sending a packet on multiple paths during handoff reduces loss
When a packet is lost on one path due to handoff, the packet is still available on the other paths
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding NodeCOA1
Path1 to COA1
Mobile Node COA1 Lifetime 1
Mobile Node COA1 Lifetime 1
COA1 is registered to Home Agent and Corresponding Node and Path1 is used to send packets to COA1
Basic Ideas Preventing a loss due to handoff
Sending a packet on multiple paths during handoff reduces loss
When a packet is lost on one path due to handoff, the packet is still available on the other path
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
Path1 to COA1
Path2 to COA2
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
Mobile Node COA1 Lifetime 1
COA2 Lifetime 2
Path2 to COA2 and path1 to COA1 are both used to multicast data packets to the mobile node
Basic Ideas Preventing a loss due to handoff
Sending a packet on multiple paths during handoff reduces loss
When a packet is lost on one path due to handoff, the packet is still available on the other paths
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA2
Mobile Node COA2 Lifetime 2
Mobile Node COA2 Lifetime 2
Path2 to COA2
While the mobile node moves out of the transmission range of base station1, it loses COA1 but the data packets are continuously available through path2 to COA2
Basic Ideas Exploit different amounts of bandwidth
Multi layer video transmission on multiple paths during handoff
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
Path2 to COA2
Path1 to COA1
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
Mobile Node COA1 Lifetime 1
COA2 Lifetime 2
Data belong to Basic LayerData belong to Enhanced Layer
Background Techniques Networking layer technique
Multi-homing Mobile IP
Transport layer technique TCP Friendly Rate Control (TFRC)
Application layer technique Source Adaptive Multi-layer encoder
Background Techniques Network layer technique
Multi-homing One host gets multiple IP addresses Schemes to support multi-homing
DHCP protocol in IPv4 IPv6 address auto-configuration and multi-
homing
Background Techniques DHCP protocol in IPv4
DHCP servers in the network can provide dynamic COA addresses for the mobile node
By sending requests and getting COAs for multiple interfaces, the mobile node can acquire multiple COAs
Multi-homed Host
Base Station 1 Base Station 2
Network Prefix 1 Network Prefix 2
DHCP request DHCP request
Background Techniques DHCP protocol in IPv4
DHCP servers in the network can provide dynamic COA addresses for the mobile node
By sending requests and getting COAs for multiple interfaces, the mobile node can acquire multiple COAs
Multi-homed Host
Base Station 1 Base Station 2
Network Prefix 1 Network Prefix 2
IPv4 Addr1 IPv4 Addr2
Background Techniques IPv6 address auto-configuration and multi-
homing By suffixing the network prefix from the
routers with host’s MAC address, multiple IPv6 COA addresses can be achieved
Multi-homed Host
Base Station 1 Base Station 2
IPv6 Network Prefix 1 IPv6 Network Prefix 2
Host MAC Addr
IPv6 Addr1 = {IPv6 Network Prefix 1||Host MAC Addr}
IPv6 Addr2 = {IPv6 Network Prefix 2||Host MAC Addr}
Background Techniques Mobile IP
Basic Mobile IP
Internet
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding NodeCOA1
BindingUpd(COA1)
BindingUpd(COA1)
Background Techniques Mobile IP
Basic Mobile IP
Internet
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding NodeCOA1
Mobile Node COA
1
Packet
Lifetime1
Background Techniques Mobile IP
Basic Mobile IP
Internet
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding NodeCOA1
Path1 to COA1
COA
1
Packet
COA
1
Packet
Mobile Node COA
1
Lifetime1
Background Techniques Mobile IP
Options used Simultaneous binding (to support multi-
homing)
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
BindingUpd(COA1)
BindingUpd(COA1)
Background Techniques Route optimization
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
Packet
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
Background Techniques Route optimization
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
BindingUpd(COA1,COA2)
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
Background Techniques Route optimization
InternetBase Station2
Base Station1
Mobile Node
Wireless Gateway
Home Agent
Corresponding Node
COA1
COA2
PacketCOA1
PacketCOA1
PacketCOA1
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
COA2 Lifetime 2
Mobile Node COA1 Lifetime 1
Background Techniques Transport layer technique
TCP Friendly Rate Control (TFRC) We use TFRC end-to-end rate control
algorithm instead of TCP To avoid the high fluctuation of transmission
rate resulting from the saw tooth shaped TCP window dynamics
Background Techniques TFRC calculates the transmission rate
using an equation below
Packet loss rate p is calculated through a short history of observed packet loss, through a weighted averaging method
)*321(**8/*3*3/*2 2nominalpppTpRTT
MTUR
rto
k
iiii LLwp
11/1
Nominal bandwidth
TFRC throughputTCP throughput
0
0.6
1.2
1.8
2.4 3
3.6
4.2
4.8
5.4 6
6.6
7.2
7.8
8.4 9
9.6
10
.2
10
.8
11
.4 12
12
.6
13
.2
13
.8
14
.4 15
15
.6
16
.2
16
.8
17
.4 18
18
.6
19
.2
19
.8
20
.4 21
21
.6
22
.2
22
.8
23
.4 24
24
.6
Background Techniques Features of TFRC during congestion avoidance
phase: Fairness to TCP
It achieves a long run throughput equal to the nominal bandwidth that a TCP session will occupy under the same congestion status
Stable transmission rate It maintains a sustainable rate against intermittent
packet around the nominal bandwidth. Thus, the fluctuation of transmission rate due to
the saw-tooth shaped TCP window dynamics is largely reduced
Quick reaction to congestion It reacts to persistent packet losses by forcing a
reduction of transmission rate over several round trip time
Background Techniques Application layer technique
Source adaptive multi-layer encoder for stream media
Multi-layer stream media Multiple encoding layers are applied in the
encoder Base layer packets contain most critical data
for the decoder Enhanced layer packets provide additional
information to increase the quality of stream media
Background Techniques Multi-Layered Video
Multi-LayerEncoder
RawVideo
Base layer
Enhancement layer
Base LayerBase +
Enhancement Layers
Technical Background Source adaptation multi-layer encoder
Source adaptive multi-layer encoder takes ri, bi, εi as input parameters to video layer i
ri is the transmission rate for video layer i bi is the buffered bits of video layer i to be sent to
the network εi is the encoding error rate
System Architecture Multi-path transport protocol
design
Components in the Architecture Path Management Module
Exist in transport layer at both ends Keep a record of all available paths Assign rate control module for each available
path Rate Control Module
A pair of rate control modules exist at both ends for each available path
Perform end-to-end feedback-based rate control on each path
Components in the Architecture Multi-path Distributor
Exist at the sender side Calculate and report the number of
video layers and target encoding rates for video layers to the application (video encoder)
Assign appropriate paths to each video layer and send the video packets through multiple paths
Components in the Architecture Multi-path Collector
Exist at the receiver side Receive video packets from multiple
paths and reorder the buffered video streams
Deliver the video streams to application (video decoder)
Simulation Settings Simulation Scenario:
Home AgentHome Agent
Corresponding Node (source of video traffic)
Corresponding Node (source of video traffic)
Mobile Node
(receiver of video traffic)
Mobile Node
(receiver of video traffic)
Intermediate RoutersIntermediate Routers
Wireless GatewaysWireless Gateways
Distance between neighboring base stations = 500 meters
Distance between neighboring base stations = 500 meters
Base station cell coverage radius = 300 meters with link speed = 11 Mbps
Base station cell coverage radius = 300 meters with link speed = 11 Mbps
Background Traffic Nodes
Background Traffic Nodes
Base StationsBase Stations
Different Average background traffic volume in different base stations are explored in simulation
Different Average background traffic volume in different base stations are explored in simulation
Simulation Settings Compared handoff schemes:
Single path schemes with single mobile IP binding: No forwarding: no local packet forwarding for mobile
nodes is performed among base stations Basic Mobile IP technique
Forwarding: packets are relayed from the old base station to the new base station when the mobile node enters the new cell
Represent network layer mobility enhancement techniques that repair the packet loss on a broken path for an active session
Multi-path handoff scheme Handoff with multiple mobile IP bindings
TFRC rate control is employed in all schemes to achieve smooth rate for stream media application
Simulation Results Results and observations:
Video throughput when the mobile node moves from high bandwidth cell to low bandwidth cell
Multi-path Video Throughput
0
1000000
2000000
3000000
4000000
5000000
6000000
0 3 6 9
12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60 63 66Time (sec)
Bit
Rat
e (b
ps)
Total Video Throughput Base Layer Throughput
when mobile node is in a high bandwidth cell, high bandwidth is used to transmit base layer video
when mobile node is in a high bandwidth cell, high bandwidth is used to transmit base layer video
During handoff, base layer rate reduces to the rate equal to the bandwidth in the low bandwidth cell, and enhancement layer video is transmitted at the rate equal to the difference between high and low bandwidth in the two cells
During handoff, base layer rate reduces to the rate equal to the bandwidth in the low bandwidth cell, and enhancement layer video is transmitted at the rate equal to the difference between high and low bandwidth in the two cells
when mobile node is in a low bandwidth cell, low bandwidth is used to transmit base layer video
when mobile node is in a low bandwidth cell, low bandwidth is used to transmit base layer video
Simulation Results Improved throughput
Multi-path handoff scheme keeps the video throughput high but adjust the base video layer to the lower rate
Multi-path handoff scheme keeps the video throughput high but adjust the base video layer to the lower rate
With different available bandwidth in the new cellWith different available bandwidth in the new cell
Simulation Results Reduced packet loss
Multi-path handoff scheme keeps the packet loss ratio low. Base layer is protected with near-to-zero loss ratio
Multi-path handoff scheme keeps the packet loss ratio low. Base layer is protected with near-to-zero loss ratio
With different available bandwidth in the new cellWith different available bandwidth in the new cell
Simulation Results Improved goodput
With protection of base layer, the goodput is improved in terms of smooth video frame rate
Video Demo Demo scenario Received Video
Raw video at the sender
Video Demo
Raw video at the sender
Received video stream
Single path w/o ForwardingSingle path w/o Forwarding
Single path w/ ForwardingSingle path w/ Forwarding
Multi-path HandoffMulti-path Handoff
Conclusion Contributions
Integrate multi-layer encoding, multi-homed mobile nodes through a multi-path transport protocol
Provide smooth end-to-end stream media handoff with wide range of bandwidth changes
Conclusion Merits of multi-path handoff
Less packet loss during handoff duplicated packets are transmitted through
multiple paths during handoff Quality improvement
Because more important data (e.g., base layer video) is transmitted over multiple paths during handoff
Minimum deployment in network Only the end systems are needed
http://netresearch.ics.uci.edu/ypan/MPATH_strm Thank you!!!