Guaranteed services
in heterogeneous wireless
access networks
Giulio Iannello
Università Campus Bio-Medico di Roma
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Who we are
• Università Campus Bio-Medico di Roma: young
institution borne in 1993 around a Faculty of
Medicine
• In 1999 started a Faculty of Engineering with a
course in Biomedical Engineering
• Tight integration between the two Faculties
• Fields of interest: informatics, system modeling,
biomaterials, biomedical instruments, robotics
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Who we are
• Research group on Computer Networks and
Advanced Distributed Applications
– COFIN project: Scalability and Quality of Service in Web
Systems (closed)
– FIRB project: Wide-scalE, Broadband, MIddleware for
Network Distributed Services (active)
– Hospital Information System for Students (HISS) project
funded by Hewlett-Packard (active)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Who we are
• Contributors:
–
–
–
–
–
–
–
Filippo Cacace
Maria Cinque
Michele Crudele
Stefano Za
Massimo Bernaschi (CNR IAC)
Pierluigi Salvo Rossi (Napoli Federico II, DIS)
Luca Vollero (Napoli Federico II, DIS)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Motivations
• Making Internet services accessible anywhere,
anytime, anyhow, and by anyone is a research field
that emerged recently
• W3C Device Independence (DI) Activity focuses on
making Web accessible anytime and anyhow
– many access mechanisms (including mobile devices)
– many modes of use (including multimedia ones)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Motivations
• DI can be considered from three perspectives:
– user
– authoring techniques
– delivery mechanisms
• Our activity focuses mainly on the third item and
concerns system support to service guarantees in
the Device Independence vision
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Motivations
Delivery mechanisms perspective
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Motivations
• The delivery subsystem should be able to reserve
resources needed to deliver services in a highly
dynamic environment
• Our activity on these “traditional” Quality of Service
issues is currently focused on:
– heterogeneous wireless access networks
– dynamic changes in network configuration and workload
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Motivations
• Service adaptation: a complementary concept to
provide effective support to universal access:
• Adaptation to access media
– bandwidth, reliability, security
• Adaptation to the interface (terminal device)
– screen, power consumption, computing power
• Adaptation to the context
– localization, time, other circumstances, preferences
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
QoS support in 802.11
• Supporting traffic differentiation in 802.11 WLAN
(infrastructured configurations)
– layer 3 management for downstream traffic
– for upstream traffic we have proposed a minor
modification to MAC protocol at the base station (called
Frame Dropping)
– can be implemented at firmware level, no change
required to mobile stations
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
QoS support in 802.11
if ACKs are dropped, the MS
perceives channel congestion
MS increase its CW
and this induces
traffic differentiation
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
QoS support in 802.11
Channel utilization (saturation)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
QoS support in 802.11
Comparison with DFS (CBR flows)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Overall channel utilization (CBR flows)
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
QoS support in 802.11
• Forthcoming standard 802.11e
– advanced protocol with enhanced scheduling
mechanisms at MAC layer
– performance modeling of throughput and delay in
saturation and non saturation conditions (Luca Vollero
visiting Albert Banchs/Madrid—Carlos III)
– medium term goal: strategies for on-line configuration of
MAC parameters
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Mobility and seamless connectivity
• Integration of WLANs and 2.5G/3G cellular
networks
• Loosely-coupled approach: Mobile IPv6
• Focus on multi-homed mobile hosts: vertical handoff
– seamless and efficient handoffs
– handoff policies
– cooperative multi-homed connectivity
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Mobility and seamless connectivity
• IPv6
Mobility
Testbed
• Operative
at Campus
Bio-Medico
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Mobility and seamless connectivity
• Vertical handoff performance improvement
• Performance analysis of transport protocols during
handoffs
– TCP
– UDP/RTP
• Intelligent handoffs through rule-based management
– merging of preferences and other context information
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Mobility and seamless connectivity
forced handoff (WLAN  3G)
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
handoff vs. offered workload
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Adaptive streaming
• CC/PP capable clients and web servers
– Intel CC/PP framework, Java-based adaptation modules
– Profile Resolution Engine (DICO—UNIMI)
– on-line assessment of network performance
• Transcoding modules
– algorithms for trading-off reproduction quality and bitrate
– real-time multimedia processing (RT-MMP) toolkit
• Adaptive RTP server
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Adaptive streaming
Intel CC/PP framework
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
Adaptive streaming
Profile’s
repository
Web Server
HTTP Request + CC/PP
Profile
HTTP Response
Client
1. Client Profile learning
10.
3.
4.
5.
The
After
This
A
connection
server
servlet
client’s
replies
retrives
via
choice,
RTP
to
client’s
the
is
estabilished
client
server
info,
with
calls
from
an
for
the
1.
2.
8.
7. The
The
This
The
device
web
infos
Video
server
are
requests
Server
sent
(CC/PP
sendes
to
a
the
web
aware)
“probe
Adapter
page
supplies
via
traffic”
HTTP
to to
6.
9.
Now
servlet
the
Adapter
now
has
Engine
to
contact
determines
the
“right”
the
adapted
Adapter
repository,
the
streaming
Engine
web
topage
know
video
in
its
which
constrains
there is
load
the
client
device’s
to
profile
know
the
into
network’s
a
DB
status
Video
bottelneck
supplying
how to
to
adapt
itits
client’s
the video
ID
UsingServer,
CC/PP,
it sends
also
infos
movies’
listand
(degradator factor)
Probing
Adapter
engine
(servlet)
2. Environment learning
RTP
3. Info merging
Video Server
+ degradator
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services
End
Thank you
Questions?
Università Campus Bio-Medico di Roma
Facoltà Di Ingegneria — Ingegneria Biomedica
Wide-scalE, Broadband, MIddleware
for Network Distributed Services