Transcript HomeRF Technical Overview

Property of the HomeRF Working Group
Technical Overview
This presentation is provided by the HomeRF Working Group.
Direct questions or requests for softcopy to:
[email protected], 503-291-2563
Or contact HomeRF Communications Chairman, Wayne Caswell
([email protected], 512-335-6073)
Property of the HomeRF Working Group
Technical Overview Topics
• Toll-quality Voice & Streaming Media
• Data Throughput, Range & Attenuation
• Security & Interference Immunity
• Power Consumption & Form Factor
• Cost
Property of the HomeRF Working Group
HomeRF Node Types
Broadband Internet
Wired network
Control Point
(CP Class 1)
Cordless Handset
(I-node)
isochronous
Laptop
(A-node)
asynchronous
Internet Appliance
(SA-node)
Audio Headset
(S-node)
streaming
Property of the HomeRF Working Group
OSI 7-Layer Network Stack Model
7. Application
6. Presentation
HomeRF Specification uses,
references, or “maps into”
existing network layers.
5. Session
4. Transport
3. Network
{
HomeRF Specification
modifies existing technology
2. Data Link (MAC)
1. Physical (PHY)
Property of the HomeRF Working Group
Network Layer View
Existing Upper Layers
UDP
TCP
DECT
IP
HomeRF MAC Layer
CSMA/CA
Priority
CSMA
TDMA
HomeRF PHY Layer
“Ethernet”
Data Path
Streaming
Media Path
Toll-Quality
Voice Path
MAC Layer
PHY Layer
2.4 GHz FH
BACKUP
Property of the HomeRF Working Group
HomeRF Specification Basics
Contention-based “Wireless Ethernet”
Reserved time TDMA
Constant
envelope FSK
modulation
Conventional
synthesizer
Plus priority access and time
reservation
Plus re-transmission
option
0.8, 1.6, 5, 10
Mbps data rates
Beacon
HomeRF Frame
Property of the HomeRF Working Group
MAC Layer Basics
Bulk of time is allocated
to data networking
time
Data Networking
1
Voice Calls
Hop
Re-Transmit
2
Priority Streams
Within data networking time,
streaming media sessions
get priority access
Reserved time period
based on number of
active voice calls
If voice packets fail, they can
be re-transmitted at the start
of the next frequency
Property of the HomeRF Working Group
Superframes and Subframes
20 ms
fN
Data#1
Ack
#1
Hop
Data#2
Ack
#2
Data#3
Ack
#3
All asynchronous traffic
10 ms
fN+1
fN+2
Hop
fN+3
fN+4
Hop
B
10 ms
Data#4
Ack#
4
Dn
#1
Up
#1
Hop
B
Data#5
Ack#
5
Dn
#1
Up
#1
Data#7
Ack#
7
Dn
#3
Up
#3
Beacon is added for Isochronous traffic and frame length is reduced to 10ms
B
Data#6
Ack#
6
Dn
#3
Dn
#1
Up
#3
Up
#1
Hop
B
Second call is added
First call ends. Frame reordered.
20 ms
fN+5
Data#8
Hop
Ack
#8
Data#9
Ack
#9
Data#10
Ack
#10
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Bandwidth Requirements
Application
Speed Required
Text
Telephone (QoS, Latency)
Color Image
Digital Photo
Digital Music (QoS)
Video Conferencing
MPEG-4 SDTV VoD (QoS, jitter)
MPEG-4 HDTV VoD 720p (QoS, jitter)
MPEG-2 HDTV 1080i (QoS, jitter)
300 bps
8 – 64 Kbps
25 – 2,500 K bytes
1,000 – 10,000 K bytes
128 – 700 Kbps
384 – 2,000 Kbps
250 – 750 Kbps
4,500 Kbps
20,000 Kbps
Property of the HomeRF Working Group
Technical Overview Topics
• Toll-quality Voice & Streaming Media
• Data Throughput, Range & Attenuation
• Security & Interference Immunity
• Power Consumption & Form Factor
• Cost
Wideband Frequency Hopping
Property of the HomeRF Working Group
HomeRF improves performance of 802.11 FH
Enabled by FCC rule change in August 2000, ETSI rule change in December 2001
75 1 MHz
channels for 1.6
Mbps data and all
voice
communications
15 5 MHz
channels for 5
and 10 Mbps data
modes
5 MHz Superchannel
f
1 MHz
Base Channel
Property of the HomeRF Working Group
RANGE: Signal Strength
Diminishes with Distance
0.8-1.6 Mbps
5 Mbps
Advertised
Range
150’
Advertised Data Rate: 10 Mbps
0’
~5 Mbps
~2.5 Mbps
~0.4-0.8 Mbps
85’
130’ 150’
Nominal throughput (Mbps)
Property of the HomeRF Working Group
Performance over Distance
HomeRF provides real-time media
streaming to more nodes over a
greater distance.
6
5
4
MPEG2 Video
3
2
1
Broadband/ MPG 4 Video
Dial-up / MP3 Audio
0
10'
20'
30'
40'
50'
60'
70'
80'
90'
100' 110' 120' 130' 140' 150'
Source: Practical and Theoretical Calculations
Attenuation: Signal Strength
Wood and plaster Walls or Floors
are OK. Even Brick.
BUILDING WALL
Property of the HomeRF Working Group
Diminishes through Materials
Metal and thick rock block the RF
signals.
The Higher the
Frequency, the
more signal loss.
5 GHz is worse
than 2.4 GHz.
Multi-path in Homes:
Property of the HomeRF Working Group
More Absorption, Less Reflection
Signals can arrive at
different times and
cancel each other out.
Property of the HomeRF Working Group
Technical Overview Topics
• Toll-quality Voice & Streaming Media
• Data Throughput, Range & Attenuation
• Security & Interference Immunity
• Power Consumption & Form Factor
• Cost
Property of the HomeRF Working Group
is Secure and Reliable
•
•
•
Frequency Hopping Spread Spectrum
– Invented for the US Military to avoid jamming,
denial of service, and eavesdropping
Performance with Interference
– Microwave ovens, cordless phones,
baby monitors, video senders, neighbors
– High Density Apartments
Security Layers
•
•
•
•
•
•
•
Application Layer Security Option
128-bit Encryption Option
Standardized Teach/Learn
24-bit Network ID
Random Frequency Hopping
Spread-Spectrum
Digital
Typical Wi-Fi configuration with
3 non-overlapping channels.
BUILDING WALL
is Secure and Reliable
Access from
car or hilltop
???
BEWARE: RF signals can penetrate walls
Interference:
FHSS
DSSS
Time
Time
2.5 GHz
Frequency
Property of the HomeRF Working Group
HomeRF hops around it
2.4 GHz
IEEE 802.11b waits for
Interference to go away
Property of the HomeRF Working Group
Active Interference Avoidance
Spectral / Temporal Characteristics of Microwave Ovens
Power
Spectral
Density
Next Next
hop hop
clear clear
Next
hop
clear
Next Next
hop hop
clear clear
Used ISM band
Frequency
(75 MHz)
Average Power Spectrum
(10 to 30 MHz)
Property of the HomeRF Working Group
Active Interference Avoidance
10 ms
Active calls
Active data traffic
fN
Hop
Beacon
Data 1
Ak1
Data 2
Dn2
Up2
Dn5
Up5
Interference 1
contacts fN
Control point allocates
retry of up/down 2
fN+1
Hop
Beacon
Dn2
Up2
Data packet
succeeds on retry
Data 2
Ak2
Normal calls continue
Dn2
Up2
Dn5
Latency is bounded to 10 ms even in the presence of interference
Up5
IEEE 802.11b
Property of the HomeRF Working Group
Signal Strength
802.11b – DSSS using channel 3
(static frequency)
Frequency over Time
2.50 GHz
2.4
2.5 GHz
2.45 GHz
2.40 GHz
0
250
500 s
Source: Celerity Digital Broadband Test
Bluetooth™
Property of the HomeRF Working Group
Signal Strength
Bluetooth Headset signal
31.25 µs between pulse pairs
125 µs between pulse sets
Frequency over Time
2.50 GHz
2.4
2.5 GHz
2.45 GHz
2.40 GHz
0
250
500 s
Source: Celerity Digital Broadband Test
2.4 GHz Cordless Phone
Property of the HomeRF Working Group
Signal Strength
Multiple Channel Cordless Telephone
Transmit Receive on separate channels
Channel selection is arbitrary
Frequency over Time
2.50 GHz
2.4
2.5 GHz
2.45 GHz
2.40 GHz
0
250
500 s
Source: Celerity Digital Broadband Test
Coexistence within ISM band
Property of the HomeRF Working Group
Signal Strength
WLAN 802.11b
Bluetooth™
Cordless Telephone
Frequency over Time
2.50 GHz
2.4
2.5 GHz
802.11b politely waits
for interference to go
away – potentially a
very long time with
cordless phones.
Bluetooth interference,
at 1600 hops/sec can
also be severe.
2.45 GHz
2.40 GHz
0
250
500 s
Source: Celerity Digital Broadband Test
Property of the HomeRF Working Group
Technical Overview Topics
• Toll-quality Voice & Streaming Media
• Data Throughput, Range & Attenuation
• Security & Interference Immunity
• Power Consumption & Form Factor
• Cost
Simple Design: enables small form
Update for 2.0?
Property of the HomeRF Working Group
factor for embedded apps
•
•
•
•
•
Smallest WLAN form factor
1.6 Mbps and full home coverage
< 10mW standby power draw
Full TCP/IP connectivity
Ideal for handheld Internet appliances,
personal imaging and audio devices
Specifications:
Physical
• Type II size, < 20 grams
• 0 – 40 degree C operation
• CE, EMC-EEC 89/336 Compliant
Electrical
• 3.3 V, 120mA Rc; 250mA Tx modes
• 3mA standby mode
Property of the HomeRF Working Group
Hand Held Trends
•
•
Larger, higher resolution Displays
with more Colors
More Performance, Less Cost
– e.g. Video streaming
•
•
•
•
•
•
Better Text rendering
Wireless (WAN, WLAN, PAN)
PDA becomes Phone, MP3…
Phone becomes PDA, MP3…
Digital Imaging
PocketPC gains some ground
– Palm still has >70% share
With Microsoft ClearType, palmsized devices can act as eBooks.
Property of the HomeRF Working Group
Technical Overview Topics
• Toll-quality Voice & Streaming Media
• Data Throughput, Range & Attenuation
• Security & Interference Immunity
• Power Consumption & Form Factor
• Cost
Property of the HomeRF Working Group
Cost Roadmap parallels DECT
•
DECT is a leading indicator for HomeRF
– 6 generations of architecture evolution
– HomeRF comes in well down the learning curve
•
Complexity is similar
– HomeRF Baseband ROM/Flash about 2X DECT
– Radio will reuse Bluetooth/DECT Low-IF IP
•
HomeRF BOM cost will approach DECT
at same volumes
– Basic HomeRF functionality (voice + 10Mbps)
– Additional SW & HW depends on product features
Property of the HomeRF Working Group
Cost Synergies
•
Easy compatibility with OpenAir
– HomeRF and OpenAir share a common PHY
(dual MAC client devices available now)
– OpenAir has over 1M devices from over 20
different vendors already deployed in the field
•
Multi-mode client devices with Bluetooth
– HomeRF and Bluetooth have similar PHY
(multi-MAC client devices, such as a PCMCIA or
Compact Flash card, are feasible and expected
in 2002)
Property of the HomeRF Working Group
Cost Synergies, cont.
•
•
Multi-mode / Multi-band clients
–
–
–
–
–
–
PCS / GSM phones
802.11b / .11g (DSSS / OFDM)
802.11b / Bluetooth (DSSS / FHSS)
802.11b / .11a (2.4 / 5 GHz)
WLAN / WAN (for mobile workers)
Easy to include support for HomeRF
Adds much needed Flexibility
– Automatically sense and adapt to networks
Simple Design: enables Inexpensive
Property of the HomeRF Working Group
2-chip solutions
Top Side
RFIC
Integrated
Baseband
Bottom Side
Flash
Property of the HomeRF Working Group
Summary
•
Ideal for the Broadband (voice, data, entertainment)
•
Designed and optimized for Households & SOHO:
•
Smooth roadmap to 20 Mb/s and beyond
•
More information at www.HomeRF.org
– Blends several technologies to enable Digital Convergence
– Broadband data at Ethernet speeds “plus” toll-quality voice
and streaming media
– Simplicity, Security/Privacy, Interference, Cost, Applications
– Multi-band support for 2.4 GHz and 5 GHz (802.11a)
– Learning Center for W.Papers, Presentations, etc.
Wireless Choices
for the Broadband Internet home
Property of the HomeRF Working Group
ATTRIBUTE
HomeRF
Bluetooth
802.11b
Cost

Security

~
Interference Immunity


Toll-Quality Voice Support

~
Streaming Media Support

~
Data Throughput

X

Range

X

Power Consumption


X
~
Form Factor


X
~
Network Topology

~
~
Roaming Outside the Home
~
~
~
Legend:
 - Advantage
~ - Adequate

~

X
X
~
X
X
~
X - Disadvantage