Transcript Towards Wireless Overlay Network Architectures

Beyond Third Generation
Cellular Networks:
The Integration of
Internet and Telephony
Technology
Bridge to the
Future
Prof. Randy H. Katz
UC Berkeley
AT&T Cambridge Laboratory
10 September 1999
http://iceberg.cs.berkeley.edu
Cellular “Core” Network
1
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
2
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
3
Mobile Telephone & Internet Users
Millions
700
600
Mobile Telephone
Users
500
Internet Users
400
300
200
100
0
1993 1994 1995 1996 1997 1998 1999 2000 2001
Year
Source: Ericsson Radio Systems, Inc.
4
Shift Toward Digital Mobile
Access Network
Millions of
Subscribers
700
600
500
400
300
Digital
200
100
0
Provides
a ubiquitous
infrastructure
for wireless
data as well
as voice
Analog
1993 1994 1995 1996 1997 1998 1999 2000 2001
Year
Source: Ericsson Radio Systems, Inc.
5
Data Dominates
United States Network Traffic Growth (gigabits, bn)
16
14
12
10
Voice
8
IP
6
4
2
05
20
04
20
03
20
02
20
01
20
00
20
99
19
98
19
97
19
96
19
95
19
19
94
0
Source: Nortel in The Economist, 13 Mar 99
6
Internet Telephony
Analog Voice to
Packet Data
Local Call
Packet Data to
Analog Voice
Local Call
Internet
Gateway
Gateway
• High Latencies/Dropped Packets being solved
• Short term: circuit-switched local infrastructure
plus packet-switched wide-area infrastructure
• Longer term: migration towards “always on” digital
broadband data connections
7
Core Network Becomes
Data-Oriented
Local Switch
Interexchange
Local Exch
Network (IXC)
Net (LEC)
Local Switch
IWF + Router
Local Exch
Net (LEC)
Voice Traffic
Connection-Oriented
Local Exch
Local Switch
PSTN
Local Switch
IWF + Router
Local Exch
Data Traffic
Packet-Oriented
Access
Network
Local Gateway
IP-Based WAN
Core Network
Local Gateway
Access
Network
8
Core Network Becomes
Data-Oriented
VoIP Gateway
Packet-Oriented
VoIP Gateway
IP-Based WAN
Router
Router
Access
Network
Access
Core Network
Network
• Routing infrastructure with support for
differentiated services
• Open question: service-level agreements that
span multiple ISPs
9
Smart Appliances/Thin Clients
PDA
PCS
Qualcomm PDQ Phone
10
• Top Gun Wingman
– “Thin” presentation layer in PDA with
full rendering engine in wireline proxy
• Top Gun MediaBoard
– Participates as a reliable
multicast client via proxy in
wireline network
11
Important Trends Revisted
• Multimedia / Voice over IP networks
– Lower cost, more flexible packet-switching core network
– Simultaneous support for delay sensitive and delay insensitive
flows via differentiated services
• Intelligence shifts to the network edges
– Third-party functionality downloaded into Information
Appliances like PalmPilots
• Programmable intelligence inside the network
–
–
–
–
Proxy servers intermixed with switching infrastructure
Mobile/extensible code, e.g., JAVA: “write once, run anywhere”
Rapid new service development
Speech-based services
12
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
13
The Future: Internet-based
Open Services Architecture
“Today, the telecommunications sector is beginning to
reshape itself, from a vertically to a horizontally
structured industry. … [I]t used to be that new
capabilities were driven primarily by the carriers. Now,
they are beginning to be driven by the users. … There’s a
universe of people out there who have a much better idea
than we do of what key applications are, so why not give
those folks the opportunity to realize them. … The
smarts have to be buried in the ‘middleware’ of the
network, but that is going to change as more-capable
user equipment is distributed throughout the network.
When it does, the economics of this industry may also
change.”
George Heilmeier, Chairman Emeritus, Bellcore
14
Transparent Information Access
Speech-to-Text
Speech-to-Voice Attached-Email
Call-to-Pager/Email Notification
Email-to-Speech
All compositions
of the above!
Universal In-box
Policy-based
Location-based
Activity-based
15
Composable Services
• E.g., voice control of A/V devices in a “Smart Room”
–
–
–
–
Multistage processing transformation
Strongly typed connectors
Service discovery service
Automated path generation
Path
Audio
Microphone
Cell phone
ICSI
Speech
Recognizer
Text
Text to
Command
A/V
Devices
Cmd
Room
Entity
Response
to Client
16
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
17
ICEBERG: Internet-based CorE
BEyond the thRid Generation
• The Challenge
– Developing service intensive, network-based, real-time applications
– Securely embedding computational resources in the switching fabric
– Providing an open, extensible network environment: heterogeneity
• Computing
– Encapsulating legacy servers & partitioning “thin” client functionality
– Scalability: 100,000s of simultaneous users in the SF Bay Area
• High BW IP backbones + diverse access networks
– Different coverage, bandwidth, latency, and cost characteristics
– Third generation cellular systems: UMTS/IMT2000
– Next gen WLANs (Bluetooth) & broadband access nets (DSL/cable)
• Diverse appliances beyond the handset or PC
– Communicator devices plus servers in the infrastructure
18
Project Goals
• Demonstrate ease of new service deployment
– Packet voice for computer-telephony integration
– Speech- and location-enabled applications
– Complete interoperation of speech, text, fax/image across the
four P’s: PDAs, pads, pagers, phones)
– Mobility and generalized routing redirection
• Demonstrate new system architecture to support
innovative applications
– Personal Information Management
» Universal In-box: e-mail, news, fax, voice mail
» Notification redirection: e.g., e-mail, pager
– Home networking and control of “smart” spaces, sensor/actuator
integration
» Build on experience with A/V equipped rooms in Soda Hall
19
Experimental Testbed
Velo
Nino
IBM
WorkPad
MC-16
Motorola
Pagewriter 2000
CF788
306 Soda
405 Soda
326 Soda “Colab”
GSM BTS
TCI @Home
Smart Spaces
Personal Information Management
WLAN /
Bluetooth
Pager
SimMillennium
Network
Infrastructure
H.323
GW
Millennium Cluster
Millennium Cluster
20
Internet-Scale Systems
Research Group
Personal Information Management and “Smart Spaces”
Distributed
Videoconferencing
& Room-scale
Collaboration
Speech and Location
Aware Applications
Speech and Location
ICEBERG
Aware Applications
Computer-Telephony Services
ICEBERG
Computer-Telephony Services
MASH Media Processing Services
TranSend Extensible
Proxy Services
Active Services Architecture
Distributed Computing Services: NINJA
Computing and Communications Platform: Millennium/NOW
21
NINJA Distributed Computing Platform
• Bases (1M’s)
–
–
–
–
–
scalable, highly available
persistent state (safe)
databases, agents
“home” base per user
service programming
environment
Wide-Area Path
• Active Proxies (100M’s)
– not packet routers, may be AN
nodes
– bootstrap thin devices into
infrastructure
– soft-state and well-connected
• Units (1B’s)
–
–
–
–
sensors / actuators
PDAs / smartphones / PCs
heterogeneous
Minimal functionality:
“Smart Clients”
Jini
devices
22
ICEBERG Principles ...
• Potentially Any Network Services (PANS)
– Any service can from any network by any device;
network/device independence in system design
• Personal Mobility
– Person as communication endpoint with single identity
• Service Mobility
– Retain services across networks
• Easy Service Creation and Customization
– Allow callee control & filtering
• Scalability, Availability, Fault Tolerance
• Security, Authentication, Privacy
23
ICEBERG Architectural Elements
• ICEBERG Access Point (IAP)
– Encapsulates network specific gateway (control and data)
• ICEBERG Point of Presence (iPOP)
– Performs detailed signaling
» Call Agent: per communication device per call party
» Call Agent Dispatcher: deploy call agent
• Name Mapping Service
– Mapping between iUID (Iceberg Unique ID) and service end point
• Preference Registry
– Contains user profile:service subscription, configuration. customization
• Person Activity Tracker (PAT)
– Tracks dynamic information about user of interest
• Automatic Path Creation Service
– Creates datapath among participants’ communications devices
24
Transformation and Redirection
Pager
GW
Cellular
Network
IAP
IAP
Transducer
IAP
Agent
GW
IAP
IP Core
WLAN
GW
Redirection
IAP
Agent
H.323
GW
PSTN
25
ICEBERG Signaling System
• Signaling System
– Distributed system w/agents communicating via signaling
protocol for call setup, routing, & control
• ICEBERG Basic Call Service
– Communication of two or more call participants using any
number of communication devices via any kind of media
– If call participant uses more than one devices, must be
used synchronously
• Basic Approach
– Loosely coupled, soft state-based signaling protocol
w/group communication
– Call Session: a collection of call agents that communicate
with each other
26
Signaling: Call Session Establishment
Alice
1
IAP
2
3
iPOP
Call Agent
Dispatcher
Call Agent
Dispatcher
3
4
Call
Agent
iPOP
Carol
16
IAP
iPOP
Call Agent
Dispatcher
13
15
Call
Agent
5
Call
Agent
12
Bob
11
7
10
Name Mapping
Service
14
8
9
IAP
6
Preference
Registry
27
Signaling: Call Control
• Call Control
– Refers to control protocol in an established call session
– Involves altering & propagating call states in the call session,
and modifying the datapath correspondingly
• Call States
– Call party identities, communication devices in use & their call
status, and datapath information on data streams involved
• Challenge
– Reliable propagation of call state changes to call agents, given
highly dynamic call session environment
» Adapt as session membership changes
» New member must be able obtain current session state
28
ICEBERG Approach for Call Control
• Call Session
– Abstraction of shared communication channel
– Level of indirection to hide identity and location of call
session members (I.e., call agents)
– Adapt to membership change
• Call State
– Soft state-based
– Maintained by each call agent in a session
29
Light-Weight Call Session
Call
Agent
Call State Table
Announce Call Session
Data Path
Table
Listen
Create/tear down
data path
Add or
remove
path
Call
Agent
Announce
Listen
Call
Agent
Create/tear down
data path
Auto Path
Creation
30
Datapath Simplification
• Separate data from control
– Isolate datapath creation from signaling
– Encapsulates media negotiation
• Powerful enabler for any-to-any communication
in ICEBERG due to its flexible composability
• Current use immature and ad-hoc
– Operator with reference count
– Operator description: what and where to run or cleanup
– Who gets to create path
31
Signaling: Fault Detection and
Recovery
• Ninja Distributed Service Environment
– Run all Iceberg components on Ninja Base
• Advantageous separation of iPOP and IAP
– IAP: network specific gateways likely maintain hard state;
Gateways are responsible for maintenance
– iPOP: light-weight call session is the key
• Detection
– IAP and iPOP send heartbeats to each other
– Loss of heartbeat implies loss of life
32
Conference Call: First Class Service
• Redefining conference call
– Call between at least two call parties with at least three
communication devices
• Conference call operations are building blocks
for services
– Add a communication endpoint
– Remove a communication endpoint
• Simplify implementation of services that
require communication endpoint changes
– Change an endpoint = remove + add
33
Example: Service Handoff
• Service handoff occurs when users switch
communication devices in midst of call session
• Enables service mobility
• Service handoff is:
– Generalized call transfer
– Special case of conference call
» User uses one device to invite another device
» Then hangs up the first device
34
Service Handoff Scenario:
Cell Phone to Laptop
handoff from
cell phone to
VAT
Cell phone
turned off
Caller
IAP
Callee
IAP
announce
announce
Listen
Listen
Start
Multicast Session
new IAP
announce
Listen
Caller
IAP2
35
Service Handoff Scenario
handoff from
cell phone to
VAT
Cell phone
turned off
Caller
IAP
Start
new IAP
announce
Listen
Multicast Session
announce
Listen
Caller
IAP2
Callee
IAP
•
•
•
•
•
Simple reliability scheme
IAP fault tolerant
Simultaneous service handoff
Multiparty calls trivial
Security through encryption
36
Comparison with SIP, H.323
• SIP Differences
– Group vs. pairwise communication
for signaling
– Light-weight session vs. tightly
coupled session
• Our Advantages
– Adaptive to dynamic call session
(i.e., call session membership
change, protocol agent fault
recovery)
– Simplicity in service
implementation
• H.323 Problems
– Complexity: no clean separation
of component protocols; many
options for doing a single task
– Extensibility: requires full
backward compatibility; each
codec is centrally registered
and standardized; not modular
– Scalability: stateful (depends
on TCP); central control for
conference call
– Services: cannot express
preferences
37
Implementation and Current Status
• Prototype system built on Ninja iSpace using
Java (~5000 line code)
• Thread programming model rather than eventdriven -- implicit state machine
• Conference call service operational
• Service handoff now being implemented
(between PSTN, GSM, WaveLAN)
• LDAP for the Name Mapping Service
• Preference Registry: forms-based
specification yielding Perl scripts
38
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
39
Summary
Data Plane
Operators
Connectors
APC
Paths
IAP
PRLS
PAT
Ninja Execution
Environment
Bases
Active
Proxies
Units
Control
Plane
40
Conclusions
• Emerging Network-centric Distributed Architecture
spanning processing and access
• Open, composable services architecture--the wide-area
“operating system” of the 21st Century
• Beyond the desktop PC: information appliances
supported by infrastructure services--multicast realtime media plus proxies for any-to-any format
translation and delivery to diverse devices
• Common network core: optimized for data, based on IP,
enabling packetized voice, supporting user, terminal,
and service mobility
41
Outline
•
•
•
•
•
Motivation
It’s all about Services
The ICEBERG Project
Summary and Conclusions
New Project: Endeavour Expedition
42
Why “Endeavour”?
• DARPA BAA 99-07: Information Technology
Expeditions
• To strive or reach; a serious determined
effort (Webster’s 7th New Collegiate
Dictionary); British spelling
• Captain Cook’s ship from his first voyage of
exploration of the great unknown of his day:
the southern Pacific Ocean (1768-1771).
– These voyages brought brought more land and wealth to
the British Empire than any military campaign
– Cook’s lasting contribution: comprehensive knowledge of
the people, customs, and ideas that lay across the sea
– “He left nothing to his successors other than to marvel at
the completeness of his work”
43
Expedition Goals
• Enhancing human understanding through
information technology
– Dramatically more convenient for people to interact with
information, devices, and other people
– Supported by a “planetary-scale” Information Utility
» Stress tested by challenging applications in decision
making and learning
» New methodologies for design, construction, and
administration of systems of unprecedented scale and
complexity
– Figure of merit: how effectively we amplify and leverage
human intellect
• A pervasive Information Utility, based on
“fluid systems technology” to enable new
approaches for problem solving & learning
44
Expedition Assumptions
• Human time and attention, not processing or
storage, are the limiting factors
• Givens:
– Vast diversity of computing devices (PDAs, cameras,
displays, sensors, actuators, mobile robots, vehicles); No
such thing as an “average” device
– Unlimited storage: everything that can be captured,
digitized, and stored, will be
– Every computing device is connected in proportion to its
capacity
– Devices are predominately compatible rather than
incompatible (plug-and-play enabled by on-the-fly
translation/adaptation)
45
Expedition Challenges
• Personal Information Mgmt is the Killer App
– Not corporate processing but management, analysis,
aggregation, dissemination, filtering for the individual
• People Create Knowledge, not Data
– Not management/retrieval of explicitly entered
information, but automated extraction and organization of
daily activities
• Information Technology as a Utility
– Continuous service delivery, on a planetary-scale, on
top of a highly dynamic information base
• Beyond the Desktop
– Community computing: infer relationships among
information, delegate control, establish authority
46
Interdisciplinary, TechnologyCentered Expedition Team
•
•
•
•
•
•
•
•
•
•
Alex Aiken, PL
Eric Brewer, OS
John Canny, AI
David Culler, OS/Arch
Joseph Hellerstein, DB
Michael Jordan, Learning
Anthony Joseph, OS
Randy Katz, Nets
John Kubiatowicz, Arch
James Landay, UI
• Jitendra Malik, Vision
• George Necula, PL
• Christos Papadimitriou,
Theory
• David Patterson, Arch
• Kris Pister, Mems
• Larry Rowe, MM
• Alberto SangiovanniVincentelli, CAD
• Doug Tygar, Security
• Robert Wilensky, DL/AI
47
Expedition Approach
• Information Devices
– Beyond desktop computers to
MEMS-sensors/actuators with
capture/display to yield
enhanced activity spaces
• Information
Utility
• Information
Applications
– High Speed/Collaborative
Decision Making and Learning
– Augmented “Smart” Spaces:
Rooms and Vehicles
• Design Methodology
– User-centric Design with
HW/SW Co-design;
– Formal methods for safe and
trustworthy decomposable and
reusable components
“Fluid”, Network-Centric
System Software
– Partitioning and management
of state between soft and
persistent state
– Data processing placement and
movement
– Component discovery and
negotiation
– Flexible capture, selforganization, and re-use of
information
48
High Speed
Learning
Decision Making
Classroom
Collaboration Spaces
E-Book
Vehicles
Info Appliances
Applications
Human Activity Capture
Event Modeling
Generalized UI Support
Transcoding, Filtering, Aggregating
Statistical Processing/Inference
Negotiated APIs
Interface Contracts
Proxy Agents
Self-Organizing Data
Wide-area Search & Index
Nomadic Data & Processing
Wide-Area Data & Processing
Movement & Positioning
Information
Utility
Automated Duplication
Distributed Cache Management
Stream- and Path-Oriented Processing & Data Mgmt
Non-Blocking RMI
PDA
Laptop
Soft-/Hard-State Partitioning
Wallmount Display
Camera
Handset Smartboard MEMS Sensor/Actuator/Locator
Information
Devices
49
Organization:
The Expedition
Cube
D
e
s
I
g
n
M
e
t
h
o
d
o
l
o
g
y
Applications
Rapid Decision Making, Learning,
Smart Spaces: Collaboration Rooms,
Classrooms, Vehicles
Information Utility
Fluid Software, Cooperating Components,
Diverse Device Support, Sensor-Centric
Data Mgmt, Always Available, Tacit
Information Exploitation (event modeling)
Information Devices
MEMS Sensors/Actuators, Smart Dust,
Radio Tags, Cameras, Displays,
Communicators, PDAs
Base Program
Option 1: Sys Arch for Diverse Devices
Option 2: Oceanic Data Utility
Option 3: Capture and Re-Use
Option 4: Negotiation Arch for Cooperation
Option 5: Tacit Knowledge Infrastructure
Option 6: Classroom Testbed
Option 7: Scalable Heterogeneous Component-Based Design
50
Putting It All Together
1. Diverse Devices
2. Data Utility
3. Capture/Reuse
4. Negotiation
5. Tacit Knowledge
6. Classroom
7. Design Methods
8. Scale-up
Devices
Component Discovery
& Negotiation
Fluid Software
Utility
Info Extract/Re-use
Self-Organization
Applications
Group Decision Making
Learning
51