Techs & Trends
GSM/CDMA/TDMA Spectrum Sharing?
Greetings,
To the best of my understanding, in Tulsa, GSM, TDMA and CDMA all make use of the 1900Mhz freqency band.
Try as I might, I just am totally unable to figure out how that can possibly work. Can anyone shed some light on that?
To the best of my understanding, in Tulsa, GSM, TDMA and CDMA all make use of the 1900Mhz freqency band.
Try as I might, I just am totally unable to figure out how that can possibly work. Can anyone shed some light on that?
...
Sure. 😁
The short answer is that the PCS (1900) band is subdivided into smaller bands. Your intuition is right - two technologies can't operate on the same frequency at the same time.
Now the long answer plus examples:
For any given area (such as Tulsa), there are six (soon to be seven) licenses issued by the FCC. Each license is owned by one company, and each covers a sub-band of frequencies within the whole PCS (1900 MHz) band.
The whole band covers 1850 - 1990 MHz, so it's actually quite a wide swath of spectrum. 1850 - 1910 MHz is what the phones transmit on, while 1930 - 1900 MHz is for the towers to transmit back to the phones.
So, for example, in Tulsa:
- Sprint owns the 30 MHz "B" block, which covers 1870 - 1885 ...
(continues)
The short answer is that the PCS (1900) band is subdivided into smaller bands. Your intuition is right - two technologies can't operate on the same frequency at the same time.
Now the long answer plus examples:
For any given area (such as Tulsa), there are six (soon to be seven) licenses issued by the FCC. Each license is owned by one company, and each covers a sub-band of frequencies within the whole PCS (1900 MHz) band.
The whole band covers 1850 - 1990 MHz, so it's actually quite a wide swath of spectrum. 1850 - 1910 MHz is what the phones transmit on, while 1930 - 1900 MHz is for the towers to transmit back to the phones.
So, for example, in Tulsa:
- Sprint owns the 30 MHz "B" block, which covers 1870 - 1885 ...
(continues)
...
🤭 I meant to say:
"1930 - 1990 MHz is for the towers to transmit back to the phones"
"1930 - 1990 MHz is for the towers to transmit back to the phones"
...
