44. Future Work
• CR with New Access Technique (OFGM(
• Network Energy Efficiency
• Massive MIMO
44
Notas del editor
Mobile Operators need to solve the key challenges for future wireless access
- There are lot of services --> need to more BW --> scarce spectrum problem
Our target is finding a band to apply LTE then extend this band by using CR
Our target is to find holes in DCS band to apply LTE technology then extend its band by using CR
To solve our problem statement
Reference power = -80 dBm to judge if this part of band is considered a hole or not --> -80dBm = DCS sensitivity and our scanned band is DCS band
Laser Meter: measuring department dimensions
EME SPY : shows power level with time - it gives power spectral density (exp: mW/cm2) – shows us all technologies
FSH6 : if we detect any hole probability, we can use it to get its freq
EME SPY shows us signal power level with time ,also shows us all technologies
This shows DCS DL from beginning the measuring process to the end
Received signal strength in NTI wireless department
We take 2 or 3 point in each room depending on it’s area then made our measurements
Max RSS is colored by the red and the min is colored by white
Etisalat has 5 MHz in DCS DL and this shows max signal power level in this 5MHz
Vodafone has 7.5MHz in DCS DL (5MHz + 2.5MHz)
Max Signal power level in Vodafone DCS DL (5MHZ) part
Max power level in Vodafone DCS DL (2.5 MHz) part
This shows a hole as max power level is less than the reference level -80dBm
In (1880 to 1900MHz) band :
At first measurement time, we found it as a hole
In second time, we found this signal
In next day we found the same problem, so we realized there is ……… send on this band
But we have to check LTE compatibility with those frequencies
After checking LTE standard we found out as follow:
1-LTE can work on the three bands except the last 15 MHz in the first band
2- First band can work only UL, second band only DL, and the third band can work DL or UL
We chose first band to be UL, the last band to be DL band, and we rejected the (1830 to 1840 MHz) band to have appropriate duplex distance between first and last band
