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1、CEA Technical Paper Home Network Wireless Technologies Evaluation: Phase I Report Comparison of Technology Performance Characteristics to Consumer Application Needs? 07/2006 Copyright Consumer Electronics Association Provided by IHS under license with CEA Licensee=IHS Employees/1111111001, User=Wing
2、, Bernie Not for Resale, 03/30/2007 20:33:30 MDTNo reproduction or networking permitted without license from IHS -,-,- NOTICE CEA Standards, Bulletins and other technical publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and purchasers
3、, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards, Bulletins and other technical publications shall not in any respect preclude any member or
4、 nonmember of CEA from manufacturing or selling products not conforming to such Standards, Bulletins or other technical publications, nor shall the existence of such Standards, Bulletins and other technical publications preclude their voluntary use by those other than CEA members, whether the standa
5、rd or other technical publications are to be used either domestically or internationally. Standards, Bulletins and other technical publications are adopted by CEA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, CEA does not assume any liability to a
6、ny patent owner, nor does it assume any obligation whatever to parties adopting the Standard, Bulletin or other technical publication. This technical publication does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibilit
7、y of the user of this technical publication to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. (Formulated under the cognizance of the CEA R7 Home Network Committee.) Published by CONSUMER ELECTRONICS ASSOCIATION 2006 Tec
8、hnology describe measurement methods for related variables (such as range versus throughput versus error rates); study QoS requirements; and consider how best to constrain and represent environmental influences on network performance (construction, impairment sources). These efforts will be affected
9、 by revised specifications, and required network interoperability and spectrum non- interference. 4. Organization Of This Report This document contains a discussion of home networking applications, a survey of wireless technologies, conclusions about the survey, a glossary of terms, three tables and
10、 a number of annexes. Table 1 lists applications and their requirements for transport on a network. The intent of this table is to inform network architects and developers about the constraints that a given application requires from a network in order to work reliably. Table 2 summarizes the results
11、 of the technology survey. Similar attributes were collected, and each technology is described. Annex A describes the report methodology and wireless attributes that were surveyed. The row headings have been carefully identified and the working group has reached consensus that these attributes chara
12、cterize the important capabilities of wireless network technologies for use in an in-home network. Careful consideration has been given to the specification entries of the annexes. The remainder of the annexes contains the results of a survey of wireless technologies and their specifications based o
13、n open standards. Information received during the summer of 2004 was used to prepare these annexes. In some cases, because the technologies are still under development, the information in the annexes may be out of date. Readers are encouraged to contact WG7 if they identify errors in or corrections
14、to any of the information presented. 5. Home Networking Applications Home Networking applications can be roughly characterized in terms of these requirements or their combinations: Bandwidth Requirements Sensitivity to Delays and / or Jitter Sensitivity to Errors Security Requirements For example: T
15、elephony (such as Voice-Over-IP) has low bandwidth requirements but high sensitivity to delays and errors and must be secure (although there is no requirement for content copy-protection). Video requirements vary based on the type of service - whether video is streaming to a display or being stored
16、for future viewing; the level of security required; the displayed resolution of the content and other factors. Sensitivity to delay may be important if, for example, the application calls for frequent channel changes, or if the display device cannot buffer the data. Delay may be unimportant if the d
17、ata is being stored or buffered. All video is sensitive to errors. Copyright Consumer Electronics Association Provided by IHS under license with CEA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 20:33:30 MDTNo reproduction or networking permitted without license fro
18、m IHS -,-,- Table 1: Application Requirements Wireless Technology Survey Phase 1 Report R7 Home Networking Standards 3 CEA Table 1 organizes wireless technologies and associated characteristics in such a way that the application developer can understand the impact of a technology choice on their app
19、lication. The Examples and Table 1 make clear the importance of defining the application fully in order to understand its requirements. No simple table is capable of detailing every possible usage model, but Table 1 provides a qualitative indication of the requirements within a range. It is left to
20、the developer to manage the necessary tradeoffs. An explanation of Table 1 column headings follows the table. Applications Typical Payload Bit Rate per Stream Streams per Connection (number) 1-way Delay Considerations Round trip Delay Considerations Jitter Considerations Sensitivity to PER /PLR (3 L
21、evels) Security Considerations Comments VIDEO Watching Broadcast TV (MPEG2) 3-20 Mbps1 1 Important for channel changing Not important Part of delay, tradeoff with buffer size High - Some errors can be handled by buffering with retransmission tradeoff with throughput May be subject to content control
22、 mechanisms (e.g. retransmission flag) Interactive TV, Video on Demand (MPEG2 stream, separate control data) 3-20 Mbps 1 Important for channel changing Important for user interactivity (control information needs timely response) Part of delay. Tradeoff with buffer size. High for video stream (see no
23、te on Broadcast TV). Low for control data (assumes robust protocols e.g. retransmission, FEC) MPEG2 stream may be subject to content control mechanisms Encryption for financial transactions Assumes separate control data for interactivity Premium channels, Pay Per View (MPEG2) 3-20 Mbps 1 May be impo
24、rtant for channel changing Not important Part of delay. Tradeoff with buffer size High (See note on Broadcast TV). May be required for copy protection, etc. Internet Video 28.8k 1500k bps 1 Not important Not important Part of delay. Tradeoff with buffer size Low if buffered High if live or multicast
25、 May be required for copy protection, etc. Privately generated video 3-30 Mbps (30 Mbps is for Digital Video) 1 Not critical Not important Not important High - Some errors can be handled by buffering with retransmission tradeoff with throughput Important for privacy Camcorder 1 CEA-775 has an option
26、 for multiplex streams up to 40 Mbps. Typical cable plants have limits up to 38.8 Mbps. Copyright Consumer Electronics Association Provided by IHS under license with CEA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 20:33:30 MDTNo reproduction or networking permitte
27、d without license from IHS -,-,- Wireless Technology Survey Phase 1 Report Table 1: Application Requirements CEA 4 R7 Home Networking Standards Applications Typical Payload Bit Rate per Stream Streams per Connection (number) 1-way Delay Considerations Round trip Delay Considerations Jitter Considera
28、tions Sensitivity to PER /PLR (3 Levels) Security Considerations Comments Security Camera 144 Kbps 8 Mbps 1 Important for human factors Important for human factors Part of delay. Sensitive if 2- way communication is included Tradeoff with buffer size Medium useful information is in stil frame conten
29、t, human compensation techniques can be employed if needed Important for privacy and chain of evidence Privacy is inherent in security systems Videophone 144 kbps (for ISDN) 2 Important for human factors Important for human factors Part of delay. Sensitive due to 2-way communication High Important f
30、or privacy Assume audio and video are multiplexed into 1 stream AUDIO Listening to radio, CD, MP3 128 kbps - 320kbps 1 Important for multi-room distribution N.A. Part of delay. Tradeoff with buffer size High- Some errors can be handled by buffering with retransmission tradeoff with throughput May be
31、 required for copy protection Wireless Stereo Speakers 64kbps- 1.5Mbps 1 Very important for synchronization N.A Sensitive due to need for short delay High May be required for copy protection Assumes one stream, speaker will extract its channel Home Theater Audio 384kbps 4.5 Mbps 1 Very Important for
32、 synchronization N.A. Sensitive due to need for short delay High May be required for copy protection Assumes one stream, speaker will extract its channel Telephony 64 kbps 2 Important for human factors Important for human factors Part of delay. Sensitive due to 2-way communication High Important for
33、 privacy DATA Command/contr ol 8 kbps N.A. Important for resource management N.A. Part of delay. Tradeoff with buffer size Low, uses retransmission Unknown Physical Security System Sensor communications 2.4 ms (no loading) Round Trip (max): Asynch: 4.8 ms (no loading) - twice the 1- way delay Jitter
34、: Asynch: 700us (no loading) but depends on network loading (collisions) Admission: Open, shared key. Authentication: Provided by 802.1x, variety of mechanisms. Encryption: Legacy uses WEP, replaced by WPA, 802.11i defines WPA2 Topology: Ad Hoc, Infrastructure, Infrastructure with multiple APs (non-
35、standard?), Managed Peer-to- Peer (Direct Link per 802.11e) Bridging is non- standard Nodes: per AP: 2007 (protocol) per AP: 64-128 (practical) Modes: See topologies Uses RTS/CTS to deal with hidden nodes Copyright Consumer Electronics Association Provided by IHS under license with CEA Licensee=IHS
36、Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 20:33:30 MDTNo reproduction or networking permitted without license from IHS -,-,- Wireless Technology Survey Phase 1 Report Table 2: Data Summary CEA 10 R7 Home Networking Standards Technology (Common Name, Standard Number) US Frequ
37、ency Bands Channelization Number of Close Proximity Networks (User Channels) Max Throughput (Payload Bit Rate) Range Characteristics (Coverage Area, Roaming) QoS Characteristics (Prioritized, Parameterized, Asynchronous*, Isochronous, Deterministic*) Robustness (Error Susceptibility*, Coexistence, T
38、olerance to Interference, Adding Nodes) Delay Characteristics (1-Way, Round Trip, Jitter) Security Characteristics (Admission, Authentication, Encryption) Network Topologies Number of Nodes Supported Modes of Operation General Comments (about the technology) WIFI g IEEE 802.11g 2.4GHz, 11 20MHz RF C
39、hannels (overlapping) Throughput: 30 Mbps Range: 150 ft (at 6Mbps and through several walls) Roaming: implementation specific Provided by the new 802.11e Prioritized (mandatory, WMM) and Parameterized (optional, WMM- SA) Errors: Retransmission at the MAC level. Multipath: Handled by OFDM equalizatio
40、n and antenna diversity. Coexistence: Dynamic channel selection for other network types, collision avoidance for other “b” and “g” networks. In-band noise: Alters modulation method and sacrifices throughput for tolerance to in- band noise. Loading: No sensitivity to nodes being added, but network ac
41、cess slows as nodes increase traffic. Other: Friendly to legacy in same family (g down shifts to b) but at slower speeds. (11e not included) (g only is better than g/b due to RTS/CTS) 1-Way (max): Asynch: 2.4ms (no loading) Round Trip (max): Asynch: 4.8ms (no loading) - twice the 1- way delay Jitter
42、: (taking from 11b data) Depends on network loading (collisions) Admission: Open, shared key. Authentication: Provided by 802.1x, variety of mechanisms. Encryption: Legacy uses WEP, replaced by WPA, 802.11i defines WPA2 Topology: ? Ad Hoc, Infrastructure ? Infrastructure with multiple APs (non- stan
43、dard?) ? Managed Peer-to-Peer (Direct Link per 802.11e) Bridging is non- standard Nodes: per AP: 2007 (protocol) per AP: 64-128 (practical) Modes: See topologies Can interoperate with 802.11b at lowers speed in “b” mode and uses RTS/CTS to deal with hidden nodes Can also extend range in a “g” only n
44、etwork by fallback to “b” mode. Copyright Consumer Electronics Association Provided by IHS under license with CEA Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/30/2007 20:33:30 MDTNo reproduction or networking permitted without license from IHS -,-,- Table 2: Data Summary W
45、ireless Technology Survey Phase 1 Report R7 Home Networking Standards 11 CEA Technology (Common Name, Standard Number) US Frequency Bands Channelization Number of Close Proximity Networks (User Channels) Max Throughput (Payload Bit Rate) Range Characteristics (Coverage Area, Roaming) QoS Characteris
46、tics (Prioritized, Parameterized, Asynchronous*, Isochronous, Deterministic*) Robustness (Error Susceptibility*, Coexistence, Tolerance to Interference, Adding Nodes) Delay Characteristics (1-Way, Round Trip, Jitter) Security Characteristics (Admission, Authentication, Encryption) Network Topologies
47、 Number of Nodes Supported Modes of Operation General Comments (about the technology) IEEE 802.15.1 2.4GHz, degrades beyond 9 piconets in close proximity * Throughput: 700 Kbps Range: 10m (specified and anecdotal) Roaming: No roaming, intended as PAN No priorities Parameterized (SCO links) Clock pro
48、vided by piconet master controller (SCO links are synchronous but not isochronous) Errors: Many FECs available (some optional). Multipath: frequency hopping Coexistence: Transmit power control for coexistence with other WLANS. Up to 9 piconets coexist well. In-band noise: transmit power control Loading: Piconet controller schedules transmissions (allocates network bandwidth), so network is stable under heavy loading. 1-Way (max): SCO links: 1.25ms (typical loading) Round Trip (max): SCO links: 1.9ms (typical loading) Jitter: 10us (max) Admissio