11/1 Spread Spectrum

Spread Spectrum, an in-depth introduction

10-25-2008 Homework

Summarize 3GPP LTE in 200 words.

11/1 OFDMA and WiMAX Technology

OFDMA and WiMAX Technology (slides)

delayed

Notice

Class of Oct 25 will begin at 2:00 p.m. because I will go to Taipei to be awarded a service medal from a nonprofit organization, Consumers Foundation.

My trip to Nova Scotia, Canada. (some in Chinese and some in English)

OSBRiDGE 3GN

802.11n Access Point and UMTS/GSM Gateway in one device.

See: HSDPA in Wikipedia

Technology beyond 3G

From 2G, 2.5G, 3G (IMS, IP Multimedia Subsystem), 3.5G/HSDPA, to 4G

Computer Communications (IT), IP-based, WiFi (Data Comm.), VoIP

Data Services

• 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), speed denoted as *u*d
• EDGE, 3 times of speed of GPRS by using 8-PSK instead of binary GMSK
• 3G, 384kbps, up to 2 Mbps, uplink is 128 kbps
• 3.5G HSDPA (High Speed Downlink Packet Access) 8-10 Mbps (R5), and 20 Mbps (R6) by MIMO, uplink is 384 kbps

Chips supporting HSDPA

OFDMA and WiMAX Technology (slides)

WiMAX vs. HSDPA

• similar:Handover, Multimedia (<>
• difference: physical, initial cost, TCO (Total Cost Ownership)

4G communication at 100 Mbit/s while moving, and 1 Gbit/s while stationary.

Pervasive networks

• simultaneously connected to several wireless accesstechnologies (Wi-Fi, UMTS for example) and can seamlessly move between them (handover)
  
• smart-radio aka cognitive radio technology to efficiently manage spectrum use and transmission power
• mesh routing protocols
• 4G may use OFDM , and also OFDMA.
• packet switching only

In general, a generation is defined by the result of technology changes over a 10-15 year time frame. Thus, 4G would refer to whatever is deployed in the 2010-2015 period, assuming 3G deployment spans the 2000-2009 period.

See

• Wikipedia 4G
• 3GPP LTE
  

Homework 10-4-2008

1. Why 2G is faster than 1G?

2. Why cellular is better than broadcast?

3. Describe a short history of development of cellular technology from 1G to 3G with a prediction of 4G and beyond.

4. Read the article that discussed the future of mobile social networks.

Due Oct 25, 2008