Mobile Wireless RF Industry

 

RF Network Evolutions

 

CDMA – > EVDO > WCDMA (includes HSDPA 1.0 High Speed Downlink Packet Access & Enhanced Uplink)

               (USA originally all CDMA)

WCDMA competes with UMTS 1900

 

GSM – > GPRS > UMTS 1900 (Europe all originally GSM)

 

1G – Analog voice

AMPS (American Mobile Phone Service)

GPRS

 

2G – Digital voice with services i.e. text messages,  

               cdmaOne (IS-95)

GSM

               US-TDMA (IS-136)

PDC (Japan)

                

2.5G –

EVDO

               GPRS

 

3G – Designed for multimedia, higher quality images & video, access to information services on private or public networks are enhanced higher data rate

               WCDMA (includes HSDPA & Enhanced Uplink)

UMTS 1900 (385Kb? Up and 0Mb/s down) (current max is? up and 2Mbps down)

              

 

3GPP (Third Generation Partnership Project)

1 - WCDMA specs and standards created by collaboration of China, Europe, Japan, Korea, USA

2 - Within 3GPP WCDMA is called UTRA (Universal Terrestrial Radio Access)

3 - Two modes FDD & TDD are both covered in WCDMA (see chapter 12)

       FDD mode most often used

       TDD mode is used when?  

4 - Downlink data speeds to 100Mb/s, latency less than 10ms,

5 - Optimized for IP-based traffic and enhanced broadcast services

6 - 3G Long Term Evolution (LTE) – uses multiple antennas to stretch downlink speeds to over 20Mb/s

7 – Within ITU 3rd generation systems are called IMT-2000 and WCDMA is most accepted system by Asia, Europe, Japan, Korea, using frequency bands around 2GHz. North America can’t use 2GHz.

 

 

3GPP2 (produced cdma2000 standard in current beta tests)

Multi carrier CDMA (cdma2000) provide bit rates up to 500Kbps within GMS carrier spacing of 200KHz.

What is frequency and is it 200KHz wide?

 

What frequency(s) and band spacing do American 1st, 2nd and 3rd gen. networks use i.e. PCS?

       USA Commercial = 800MHz?

       USA Military = 850MHz

       USA Commercial = 1900MHz

       Europe Commercial = 900MHZ

       Europe Commercial = 1800MHz

       Europe Commercial = 1920MHz - 1980MHz and 2110MHz – 2170MHz   WCDMA w/FDD

               IMT-2000 - Europe & most of Asia use two bands each with 60MHz spacing

 

 

 

Questions

SMS (Simple Message Service) text messaging goes over paging channel is that same or part of SMS or dif?

 

 

TEMS takes lead in PESQ testing – from Ericsson web site news

 

 

Cell phones can vary Tx power to accommodate cell site strength

       Does the BSC tell UE to boost Tx power?

       Does the cell site also vary Tx power?

 

 

 

 

Test Monitoring for

       Voice -

       Data -

 

RF Rx Gain

       -100db is very weak (-90db or more lost calls common)

       -75db or better about target

       -50db is very strong

 

Transmit power measured in watts and db gain normal range -43 to -98, calls may drop at -90

 

Macro Cell Site has 360 degrees antenna array usually split into 3 sectors of 120 degrees each (Alpha, Beta, Gamma)

       For higher congested areas they might add a 4th sector (downtown areas) and rarely add a 5th sector

 

UE selects one Server cell site and six Neighbor cell sites with up to 32 tracked, based on Rx level at UE cell phone or laptop air-card.

MS tells BSC to switch intracell or intercell – Handover (GSM) or Handoff (CDMA or UMTS)

 

 

OSI 7 Layer Model            PDNTSPA (Please Do Not Throw Sausage Pizza Away)

7 Application -

 

6 Presentation -

 

5 Security -

 

4 Transport -

 

3 Network -

 

2 Datalink -

 

1 Physical -

                      Spreading, modulation, signal transmission, power control, paging