Sunday, February 27, 2005
無線寬頻作業一 By: G9376603 宋懷遠
無線寬頻作業一 By: G9376603 宋懷遠
Skype business model
PChome Online表示，目前該軟體所提供的網路電話語音服務是電腦端對電腦端通話的模式，目前是免費下載，這代表講電話免錢的時代已經到來，未來將發展其他模 式的撥打方式，如從電腦端撥到市內電話及手機。當跳脫PCto PC模式時，就需要收取費用。該公司將於今年下半年推出上述服務，並以「SkypeOut」為名稱，透過SkypeOut撥打國際電話，費用是傳統電話的 十分之一。
Skype是一款語音通訊（VoIP）軟體，因此在聲音的傳遞技術上也特別加強，其主要特色如下：
音質超優，傳遞不延遲：以往的網路語音聊天，最被人詬病的就是音質差又會延遲，因此Skype特別加強語音壓縮技術，其音質比一般市話更佳，甚至可媲美 CD音質，而且聲音傳遞也不延遲。
不怕防火牆阻擋：多數的 VoIP軟體碰到了防火牆或是 NAT（網路位置傳譯）都會被擋下而無法通話，但有許多人的網路都還是架設在防火牆或 NAT之內的，而Skype利用獨特的點對點（Peer-to-peer）傳輸技術，可以避開防火牆阻擋，順利跟對方連上線。
通話不怕被竊聽：如果電話中聊到重要內容，最怕被人竊聽，Skype在通話時兩方的語音資訊都是經過加密後再行送出，所以安全性很高，不必擔心電話內容被竊聽。
可讓多人同時線上交談：Skype提供語音聊天室，最多可以支援5個人同時線上聊天，這樣就可以找一群朋友同時來聊天，或者是直接開線上會議。
另外Skype也可以傳送文字簡訊以及上傳個人照片，還能把好友名單中的暱稱修改成比較好認的名字，使用上相當方便。
為 了推廣這套軟體，原創公司也積極在全球尋找合作伙伴，PChome Online是原創公司在全球首家合作的網站，負責台灣地區的推廣。目前Skype介面修改成繁體中文後，取名為PChome-Skype，未來 PChome Online會陸續提供更多的加值服務，包括用PChome-Skype撥打到電話與手機的功能。
Source:Pchome
Skype business model
PChome Online表示，目前該軟體所提供的網路電話語音服務是電腦端對電腦端通話的模式，目前是免費下載，這代表講電話免錢的時代已經到來，未來將發展其他模 式的撥打方式，如從電腦端撥到市內電話及手機。當跳脫PCto PC模式時，就需要收取費用。該公司將於今年下半年推出上述服務，並以「SkypeOut」為名稱，透過SkypeOut撥打國際電話，費用是傳統電話的 十分之一。
Skype是一款語音通訊（VoIP）軟體，因此在聲音的傳遞技術上也特別加強，其主要特色如下：
音質超優，傳遞不延遲：以往的網路語音聊天，最被人詬病的就是音質差又會延遲，因此Skype特別加強語音壓縮技術，其音質比一般市話更佳，甚至可媲美 CD音質，而且聲音傳遞也不延遲。
不怕防火牆阻擋：多數的 VoIP軟體碰到了防火牆或是 NAT（網路位置傳譯）都會被擋下而無法通話，但有許多人的網路都還是架設在防火牆或 NAT之內的，而Skype利用獨特的點對點（Peer-to-peer）傳輸技術，可以避開防火牆阻擋，順利跟對方連上線。
通話不怕被竊聽：如果電話中聊到重要內容，最怕被人竊聽，Skype在通話時兩方的語音資訊都是經過加密後再行送出，所以安全性很高，不必擔心電話內容被竊聽。
可讓多人同時線上交談：Skype提供語音聊天室，最多可以支援5個人同時線上聊天，這樣就可以找一群朋友同時來聊天，或者是直接開線上會議。
另外Skype也可以傳送文字簡訊以及上傳個人照片，還能把好友名單中的暱稱修改成比較好認的名字，使用上相當方便。
為 了推廣這套軟體，原創公司也積極在全球尋找合作伙伴，PChome Online是原創公司在全球首家合作的網站，負責台灣地區的推廣。目前Skype介面修改成繁體中文後，取名為PChome-Skype，未來 PChome Online會陸續提供更多的加值服務，包括用PChome-Skype撥打到電話與手機的功能。
Source:Pchome
無線寬頻作業一 By: G9376603 宋懷遠
無線寬頻作業一 By: G9376603 宋懷遠
Business model Wi-Fi vs GSM
1. Wi-Fi can not support a fast roaming between cells with car speed while GSM user can be supported up to 180 Km/hr.
2. Wi-Fi use 2.4GHz for 802.11b while GSM use 900 / 1800 /1900 MHz.
The modulation technology is CDMA for Wi-Fi and TDMA+FDMA for GSM
3. GSM data connection speed is 9.6kbps while WI-Fi is 11Mbps.
GSM can be upgraded to GPRS speed fort around 100kbps.
4. GSM Cell’s coverage range is much larger than Wi-Fi,can be up to several kilo meters while the WALN can only support up to 100 meters.
5. Can you live without GSM now ?
6. The Wi-Fi charging rate is cheaper than GSM or GPRS.
In Mainland China , China Mobile provide the GPRS service with a fixed rate
of 200人民幣 per month.
In Taiwan , the carrier provide charge the rate by bytes which is much more expensive than in Mainland China.
7. Wi-Fi can support VOIP which is a great impact to GSM voice business.
Some GSM handset will be installed WLAN which allow the user to use VOIP.
Business model Wi-Fi vs GSM
1. Wi-Fi can not support a fast roaming between cells with car speed while GSM user can be supported up to 180 Km/hr.
2. Wi-Fi use 2.4GHz for 802.11b while GSM use 900 / 1800 /1900 MHz.
The modulation technology is CDMA for Wi-Fi and TDMA+FDMA for GSM
3. GSM data connection speed is 9.6kbps while WI-Fi is 11Mbps.
GSM can be upgraded to GPRS speed fort around 100kbps.
4. GSM Cell’s coverage range is much larger than Wi-Fi,can be up to several kilo meters while the WALN can only support up to 100 meters.
5. Can you live without GSM now ?
6. The Wi-Fi charging rate is cheaper than GSM or GPRS.
In Mainland China , China Mobile provide the GPRS service with a fixed rate
of 200人民幣 per month.
In Taiwan , the carrier provide charge the rate by bytes which is much more expensive than in Mainland China.
7. Wi-Fi can support VOIP which is a great impact to GSM voice business.
Some GSM handset will be installed WLAN which allow the user to use VOIP.
Saturday, February 26, 2005
2/26 Homework
1. What drives wireless broadband and makes it fly?
2. What are the impacts and implications of emergence of digital camera, IP Phone, digital TV, & digital broadcast?
3. Why all IP networks? Please explain briefly.
Reading Assignments
1. Multimedia Wireless Networks: 3 demo from Phillips and 4 articles from WiFiplanet
2. Please read the following sections before we meet next time.
M1.6~ M1.8, M1.12, F3.1~F3.3, G1
2. What are the impacts and implications of emergence of digital camera, IP Phone, digital TV, & digital broadcast?
3. Why all IP networks? Please explain briefly.
Reading Assignments
1. Multimedia Wireless Networks: 3 demo from Phillips and 4 articles from WiFiplanet
2. Please read the following sections before we meet next time.
M1.6~ M1.8, M1.12, F3.1~F3.3, G1
Friday, February 25, 2005
The State of Handhelds & VoIP
SmartPhoneToday.
Issues: Should the user be aware of the switch from Wi-Fi to GSM or vice versa?
Observation: Motorola and Skype work together.
請將你的作業寫在你的 blog
請將你的作業寫在你的 blog, 然後到
Homework 1 的Comment 登錄作業blog網址就可以了.
請勿將作業直接寫在 comment
可以參考陳一德, 謝鴻儒同學Homework 1 的方式.
另外, 謝鴻儒同學的 Homework 1 網址可以直接點選,
這是很好的做法, 更有利於前往閱讀.
Homework 1 的Comment 登錄作業blog網址就可以了.
請勿將作業直接寫在 comment
可以參考陳一德, 謝鴻儒同學Homework 1 的方式.
另外, 謝鴻儒同學的 Homework 1 網址可以直接點選,
這是很好的做法, 更有利於前往閱讀.
Saturday, February 19, 2005
2/19 Homework
1. business model of Wi-Fi City compared to GSM operation models.
2. business model of Skype
Due next Saturday 11:00 a.m.
Please write your homework at your own blog. Then post your blog URL here using
Post a comment so that your submission can be timemarked and your classmates can take a look of your work.
2. business model of Skype
Due next Saturday 11:00 a.m.
Please write your homework at your own blog. Then post your blog URL here using
Post a comment so that your submission can be timemarked and your classmates can take a look of your work.
25 million downloads of Firefox
On February 15th, exactly 99 days after it was released, Firefox 1.0 smashed through the 25 million download milestone.
http://www.spreadfirefox.com/
http://www.spreadfirefox.com/
2/19 Reading Assignments and topics for 2/26
Please read the following sections before we meet next time.
M1.1~ M1.8, M1.12, F3.1~F3.3, G1
For meeting Agenda of 2/26, please refer to the syllabus.
3. A Perspective of Wired & Wireless Broadband Networks
M1.1~ M1.8, M1.12, F3.1~F3.3, G1
For meeting Agenda of 2/26, please refer to the syllabus.
3. A Perspective of Wired & Wireless Broadband Networks
Reading Assignments
Textbooks:
(M) C. Siva Ram Murthy, B. S. Manoj Ad Hoc Wireless Networks: Architectures and Protocols Prentice Hall, 2004. 全華圖書代理進口
Reference
(G) Aura Ganz, Zvi Ganz, Kitti Wongthavarawat Multimedia Wireless Networks, Prentice Hall, 2004.
Behrouz Forouzan TCP/IP Protocol Suite McGraw-Hill, 全華圖書代理進口, 2003.
(F) Behrouz Forouzan (陳中和、吳秀峰翻譯) TCP/IP 協定精要 (TCP/IP Protocol Suite, 2/e) 2004
(W) Wireless Business News Updates: http://www.wifiplanet.com
使用說明
M2.1 表示 Murthy的書第2.1節
學期課程
1. Trends of Internet Applications and Business models
Peer to peer, Overlay Network, Google, VoIP, Skype, All IP Network, Wi-Fi, WiMax, M-Commerce
Reading Assignments: handout at Wireless Blog
2. Multimedia Applications
Video & Audio Streaming, Peer-to-Peer, Digital Money Transactions, Entertainment, File & Picture Sharing, Wireless Gaming, Voice and Telephony, Location Based Services, Telemedicine, Telematics, Car-to-Car Wireless Communications
Reading Assignments: G1
3. A Perspective of Wired & Wireless Broadband Networks
802.3, ADSL, Cable Modem, T Lines, SONET, Frame Relay, ATM, FTTx,
4. Underlying Technology at Physical Layers
5. OSI Model and TCP/IP Protocol Suite
Layers in the OSI model, TCP/IP protocol suite, addressing
Reading Assignments: M1.9~ M1.12, F2.1~F2.3, F2.5
6. QoS Fundamentals
Throughtput, Delay, Delay Variations, Loss or error Rate
7. Media Access Control
FDMA/TDMA /CDMA, 802.11, 802.16, 802.15
Reading Assignments: M1.12, M2.1 ~ M2.3, M2.5, M3.9,
8. Wireless WAN,
GPRS, UMTS, cdma2000, WAP
Reading Assignments: M3.1~ M3.6, M4.5
9. Internet Protocol
Fragmentation, Options, Checksum, IP Package
Reading Assignments: M4.1 ~ M 4.3, F8.1~F8.2
10. Transmission Control Protocol
TCP Services, Flow Control, Error Control, Congestion Control, Segment, Connection, TCP Operation, TCP Package
Reading Assignments: M4.4, F12.1~F12.14
11. Routing Protocols
RIP, OSPF, and BGP
12. Mobile IP
Reading Assignments: M4.1~ M4.3, F27.1~F27.7
13. TCP in Wireless Domains
14. Ad Hoc Wireless Networks
Issues, MAC & Routing
Reading Assignments: M5.1~M5.3, M6.1~M6.9, M7.1~M7.9
15. Wireless Sensor Neiworks
16. Internet Security
Public Key Infrastructure, Digital Signature, SSL, Firewall, NAT, Watermark
張老師簡歷
現職
- 中原大學電子工程學系研究所專
經歷
- 美國伊利諾大學香檳校區電機與電腦工程系助理教授(3年)
- 中原大學電子工程學系研究所專
- IBM 亞太區電子商務顧問 (3年)
- 蕃薯藤(Yam.com)數位科技協理 (5年)
Features of Skype
1. peer to peer, no server required, therefore, no operation cost like cellular communications
2. overlay, not relying on existing Internet protocols beyond Layer 4, resilient to malfunctions of Internet services
3. scalable, using supernodes among every 500 nodes, adaptive to constant configuration changes
4. high quality codec for crystal voice
5. strong penetration to NAT and firewalls
6. free for now and maybe forever for on-net calls
7. implementation of packet voice
8. consumes reasonable bandwidth, consumes significant CPU
9 . teleconference, voice communications for 5 parties at most
10. millions people online all the times, number keep rising.
11. provide presence like messengers, great feature compared to old phones
2. overlay, not relying on existing Internet protocols beyond Layer 4, resilient to malfunctions of Internet services
3. scalable, using supernodes among every 500 nodes, adaptive to constant configuration changes
4. high quality codec for crystal voice
5. strong penetration to NAT and firewalls
6. free for now and maybe forever for on-net calls
7. implementation of packet voice
8. consumes reasonable bandwidth, consumes significant CPU
9 . teleconference, voice communications for 5 parties at most
10. millions people online all the times, number keep rising.
11. provide presence like messengers, great feature compared to old phones
Friday, February 18, 2005
台北無線寬頻 802.16 初步架構與預算評估
Objective:
1. To overcome HFC's bottleneck and provide best-effort broadband wireless coverage
in the Metropolitan Taipei area.
2. To make use of the advanced technology and provide the scalability for future growth of the infrastructure
Basic:
A 802.16 base station can cover 40 km-square.
Therefore, if there are no obstacles such as hills, 7 base stations should be
enough to cover metropolitan Taipei.
Bandwidth:
Each station can support 72 Mbps. So the overall thoughput is as high as 504 Mbps,
equivalently, 330 T1 lines.
Benefits:
It can overcome HFC's uplink bottleneck (at 500 kbps).
802.16 can use the unlicensed 5.8 GHz (ISM band). But I have to check it this frequency is also lisense free in Taiwan.
Scalability:
When more subscribers get online, each base station can gracefully grow up to sixfold, just like the honeycomb, by just adding more
flat panel antennas and tranceivers. So the throughput grow to 3024 Mbps or 1980 T1 lines.
If further bandwidth is needed in the distant future, we can add more base stations by adding more microwave towers.
Risk:
The fundamental question is whether 7 base stations is enough. Because there are obstacles,
I don't think 7 can make it. We need some kind of terrain survey to pin down this number.
Budget:
Since Taipei is basically a basin, I would make a wild guess that 20 should suffice.
If this is a good guess, the budget to get the euipment alone is 80M TWD. Of course, we need to consider
labor cost, tower setup, among other things. So the cost would be around 100 M TWD.
Disclaimer:
I have to stress again that there are variables such as terrain features and, therefore, the report is only preliminary.
ps.
台北市十二行政區面積一覽表
區別 各行政區面積
(平方公里)
松山區 9.2878
信義區 11.2077
大安區 11.3614
中山區 13.6821
中正區 7.6071
大同區 5.6815
萬華區 8.8522
文山區 31.5090
南港區 21.8424
內湖區 31.5787
士林區 62.3682
北投區 56.8216
台北市總計面積:271.7997平方公里
1. To overcome HFC's bottleneck and provide best-effort broadband wireless coverage
in the Metropolitan Taipei area.
2. To make use of the advanced technology and provide the scalability for future growth of the infrastructure
Basic:
A 802.16 base station can cover 40 km-square.
Therefore, if there are no obstacles such as hills, 7 base stations should be
enough to cover metropolitan Taipei.
Bandwidth:
Each station can support 72 Mbps. So the overall thoughput is as high as 504 Mbps,
equivalently, 330 T1 lines.
Benefits:
It can overcome HFC's uplink bottleneck (at 500 kbps).
802.16 can use the unlicensed 5.8 GHz (ISM band). But I have to check it this frequency is also lisense free in Taiwan.
Scalability:
When more subscribers get online, each base station can gracefully grow up to sixfold, just like the honeycomb, by just adding more
flat panel antennas and tranceivers. So the throughput grow to 3024 Mbps or 1980 T1 lines.
If further bandwidth is needed in the distant future, we can add more base stations by adding more microwave towers.
Risk:
The fundamental question is whether 7 base stations is enough. Because there are obstacles,
I don't think 7 can make it. We need some kind of terrain survey to pin down this number.
Budget:
Since Taipei is basically a basin, I would make a wild guess that 20 should suffice.
If this is a good guess, the budget to get the euipment alone is 80M TWD. Of course, we need to consider
labor cost, tower setup, among other things. So the cost would be around 100 M TWD.
Disclaimer:
I have to stress again that there are variables such as terrain features and, therefore, the report is only preliminary.
ps.
台北市十二行政區面積一覽表
區別 各行政區面積
(平方公里)
松山區 9.2878
信義區 11.2077
大安區 11.3614
中山區 13.6821
中正區 7.6071
大同區 5.6815
萬華區 8.8522
文山區 31.5090
南港區 21.8424
內湖區 31.5787
士林區 62.3682
北投區 56.8216
台北市總計面積:271.7997平方公里
國外球場Wi-Fi應用
我整理了國外的應用供大家繼續思考與發揮.
國外球場Wi-Fi應用
中場check email, QQ
查球員照片,個人出賽資料
觀眾以無線寬頻照相傳輸自拍或精采畫面,使用照相PDA
包廂無線上網
精采鏡頭立即重播/慢動作 (使用Service Discovery 技術)
電台電視網路轉播
買點心,線上刷卡,點心直接端到位置上
媒體中心供記者發稿
戶外教學
今日討論
對戰軟體
球迷化妝票選
票選MVP+抽獎
球迷看完球賽之後填寫問券與抽獎
球票預售
PS:
新莊球場有 3-4 VIP rooms
國外球場Wi-Fi應用
中場check email, QQ
查球員照片,個人出賽資料
觀眾以無線寬頻照相傳輸自拍或精采畫面,使用照相PDA
包廂無線上網
精采鏡頭立即重播/慢動作 (使用Service Discovery 技術)
電台電視網路轉播
買點心,線上刷卡,點心直接端到位置上
媒體中心供記者發稿
戶外教學
今日討論
對戰軟體
球迷化妝票選
票選MVP+抽獎
球迷看完球賽之後填寫問券與抽獎
球票預售
PS:
新莊球場有 3-4 VIP rooms
mobile Internet
cellular handsets:
PHY: All digital
Signaling:
SMS, Short Message Service, up to 160 bytes
SMS, EMS use control channels while MMS use regular channels shared by data and voice.
Media Access: TDMA for multiplexing, using one of 8 time slots repeatedly
GSM, Circuit Switching, 9.6 (*2), 12.4(*2, HSCSD)
GPRS, General Packet Radio Services, Packet Switching, 9.05 kbps/13.4 kbps (*1,2,3,4)
WAP, content bearer protocol, certificate, cookies
WML, wireless markup language (or HTML-C as in i-Mode, XHTML)
MMS, Multimedia Messaging Service
Tariff
GPRS vs. GSM
pricing based on data volume or air time
Business Issues:
Will MMS make a hit?-
Function Integration
1. Fundamental questions: Do people like Swiss Army Knife? Video phone,
Recorder-TV,
British Royal Navy Sea Harrier (http://www.targetlock.org.uk/seaharrier/)
Format convergence products
2. DVD-Combo, DVD/VCD/CD
3. Card Reader, SD/SMC/MMC/CF
Advanced Applications
Positioning, LBS, GPS required for high precision
Security features
WIM: A Wireless Identity Module (WIM) can contain
both trusted and client certificates, private keys
and algorithms needed for WTLS handshaking,
encryption/decryption and signature generation.
The WIM module can be placed on a SIM card
and is then referred to as a SWIM card.
Social Issues:
base stations in communities
Near Fields
3G Technology Trends
Spread Spectrum: CDMA vs. TDMA (so called 3G)
MMS business issues
1. archiecture of MMS delivery systems
2. comparison to Internet
Principles of SS
1. from FDMA, TDMA to CDMA
2. related applications: IS-95, W-CDMA, 802.11
authentication and billing of wlan with SIM card
1. authentication
2. billing
3. coverage of both 802.11 & GPRS/3G
4. roaming across APs and WISPs
5. user base
PHY: All digital
Signaling:
SMS, Short Message Service, up to 160 bytes
SMS, EMS use control channels while MMS use regular channels shared by data and voice.
Media Access: TDMA for multiplexing, using one of 8 time slots repeatedly
GSM, Circuit Switching, 9.6 (*2), 12.4(*2, HSCSD)
GPRS, General Packet Radio Services, Packet Switching, 9.05 kbps/13.4 kbps (*1,2,3,4)
WAP, content bearer protocol, certificate, cookies
WML, wireless markup language (or HTML-C as in i-Mode, XHTML)
MMS, Multimedia Messaging Service
Tariff
GPRS vs. GSM
pricing based on data volume or air time
Business Issues:
Will MMS make a hit?-
Function Integration
1. Fundamental questions: Do people like Swiss Army Knife? Video phone,
Recorder-TV,
British Royal Navy Sea Harrier (http://www.targetlock.org.uk/seaharrier/)
Format convergence products
2. DVD-Combo, DVD/VCD/CD
3. Card Reader, SD/SMC/MMC/CF
Advanced Applications
Positioning, LBS, GPS required for high precision
Security features
WIM: A Wireless Identity Module (WIM) can contain
both trusted and client certificates, private keys
and algorithms needed for WTLS handshaking,
encryption/decryption and signature generation.
The WIM module can be placed on a SIM card
and is then referred to as a SWIM card.
Social Issues:
base stations in communities
Near Fields
3G Technology Trends
Spread Spectrum: CDMA vs. TDMA (so called 3G)
MMS business issues
1. archiecture of MMS delivery systems
2. comparison to Internet
Principles of SS
1. from FDMA, TDMA to CDMA
2. related applications: IS-95, W-CDMA, 802.11
authentication and billing of wlan with SIM card
1. authentication
2. billing
3. coverage of both 802.11 & GPRS/3G
4. roaming across APs and WISPs
5. user base
Ask the right questions. Or simply ask questions no matter what
1. What drives wireless broadband and makes it fly?
2. Explain paradigm shift: from server-centric to peer to peer, from infrastructure to ad hoc
3. What are the impacts of emergence of digital camera, IP Phone, digital TV, & digital broadcast?
4. Why all IP networks?
5. Comment on the opinion of control transfer from teleco to datacom.
2. Explain paradigm shift: from server-centric to peer to peer, from infrastructure to ad hoc
3. What are the impacts of emergence of digital camera, IP Phone, digital TV, & digital broadcast?
4. Why all IP networks?
5. Comment on the opinion of control transfer from teleco to datacom.
Syllabus: Broadband Wireless Networking Architectures and Applications
Time: 1:10 p.m. - 4:00 p.m. Saturday
Place:
Grading Policy: Participation (Presence, Challenging and Answers, & 2 Oral Presentations) 60%, Homework 40%,
Instructor: Associate Professor Yao-Jen Chang
Email:yjchang at cycu dot edu dot tw
Textbooks:
C. Siva Ram Murthy, B. S. Manoj Ad Hoc Wireless Networks: Architectures and Protocols Prentice Hall, 2004. 全華圖書代理進口
Reference
Aura Ganz, Zvi Ganz, Kitti Wongthavarawat Multimedia Wireless Networks, Prentice Hall, 2004.
Behrouz Forouzan TCP/IP Protocol Suite McGraw-Hill, 全華圖書代理進口, 2003.
Behrouz Forouzan (陳中和、吳秀峰翻譯) TCP/IP 協定精要 (TCP/IP Protocol Suite, 2/e) 2004
Wireless Business News Updates: http://www.wifiplanet.com
Tips for you to do better performance
1. 繳交作業：
文字式作業原則上使用 Blog: 請至 http://www.blogger.com 申請, 請以你的學號 (s/g開頭) 申請免費帳號。主旨欄請用以下格式 "無線寬頻作業一
" 以加速助教登錄作業成績。
2. 發表學習心得：以Blog (部落格) 發表學習心得，此部份將對Participation成績有益
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