I find that Release 4 and Release 5 of 3GPP support both IPHC and
ROHC. But which is popular and in what combination ?
In GSM and IS-95,the 0-byte header compression is used to completely
eliminate the headers for a majority of the packets during normal
operation and the functionalities available in 1-octet header scheme
is available from the lower layer functionalities.
In CDMA2000, I assume that the 'Header Removal' might be applicable
whenever the RTP/UDP/IP information is not required at the UE/MS.
However, there are other options that are available in CDMA 2000 -
1. ROHC
2. Link Layer Assisted Robust Header Compression
I understand that the limited bandwidth of wireless links makes it
impossible to transmit the entire IP/UDP/RTP header with every packet
and So,arrived the ROHC mechanism that only transmits the fields that
change rather than the entire header, but still maintain context
information.
To overcome the limitation of sending atleast 1 octet of header
information in ROHC,there is a feature that uses the synchronous
characteristics of physical channel layer to replace the compressed
header information.
But, which is widely implemented and used in the following -
CDMA2000 1X(IS-2000) / 1xRTT
CDMA2000 EV-DO (Rev 0/A/B)
Any ideas ?
Thx in advans,
Karthik Balaguru