Why is the transmitted power from BTS to a mobile phone higher in GSM900, as compared to GSM1800?
e.g.
GSM900 transmitted power from BTS: 39dBm
GSM1800 transmitted power from BTS: 36dBm
Why is the transmitted power from BTS to a mobile phone higher in GSM900, as compared to GSM1800?
e.g.
GSM900 transmitted power from BTS: 39dBm
GSM1800 transmitted power from BTS: 36dBm
as 1800 MHz is higher than 900MHz,the free space loss is higer in 1800 than 900,and so the cell size is lower in 1800 than 900,so if the operator wants to compensate this loss to have the same cell size either for 900 or 1800,it'll increase the power of BTS 1800,and if it doesn't want,the power of 1800 may be the same as 900 or less.also,can i know the source of this numbers you mentioned?
thanks in advance
the reason for gsm1800 is NOT the coverage but the capacity of cell. So naturally gsm 1800 cells are smaller and often located in areas where you need high capacity in small space (shopping mall, football stadium, etc). Those numbers you mentioned are only as example. you have to take into account also antenna gain, downtilt, lna and so on. so do not compare gsm1800 and gsm900. they are not for the same purpose
As 800MHz is a lower freq compare to 1800MHz, the lower one will have a bigger cell capacity
The higher freq will has a smaller cell capacity if we use the same power to transmit the signal
Hope it will help you guys
Best regards,
Added after 12 minutes:
cancel said:
the reason for gsm1800 is NOT the coverage but the capacity of cell. So naturally gsm 1800 cells are smaller and often located in areas where you need high capacity in small space (shopping mall, football stadium, etc). Those numbers you mentioned are only as example. you have to take into account also antenna gain, downtilt, lna and so on. so do not compare gsm1800 and gsm900. they are not for the same purpose
I agree with this post..
Usually operator use this freq (1800 -red) as a special purposes
In the rural or sub urban area a 800 MHz will be good enough for the cell capacity but in the main city, we need a bigger capacity as there are bigger users need the services
as 1800 MHz is higher than 900MHz,the free space loss is higer in 1800 than 900,and so the cell size is lower in 1800 than 900,so if the operator wants to compensate this loss to have the same cell size either for 900 or 1800,it'll increase the power of BTS 1800,and if it doesn't want,the power of 1800 may be the same as 900 or less.also,can i know the source of this numbers you mentioned?
thanks in advance
I was studying at some GSM articles, and find that transmitted power of GSM900 to be typically higher than that of GSM1800. The previous values i mentioned are just examples i quoted from some articles.
it is harder to make Power amplifiers for mobiles phones in GSM1800 than GSM900 with the same output power. So the GSM 1800 phones are less powerful.
The GSM1800 system becomes uplink limited, i.e. BTS will not be able to hear MS, while MS will be in perfect reception of BTS signal. There is no point in producing GSM1800 BTS with the same pwr output capability as for GSM900.
It was reasoned more or less as stated above, before TMA (tower mounted amplifiers) had become very common.