Radio interface protocol structure:
Note that RB vs. SRB
At the UTRAN side, RLC and above protocols are located at RNC.
MAC protocols: some functionalities are at Node B, others are at RNC.
You want to know UMTS ?
Then, first you need to be familiar with the terminologies in the below picture.
Yes!
Transport format combination (TFC) selection frequency is equal to the length of the shortest configured TTI duration.
During a given TTI, the selected transport formation combination (TFC) must reamin the same.
It can be changed by the transmitter from one TTI to another.
Such a change involves alterations in physical layer parameters suchas the spreading factor etc.
Thus, the receiver should detect the transport format combination that is being used at a given moment.
This can [...]
Transport format combination set is the set of all transport format combination.
This is equivalent to transport format set for transport format when several transport channels are multiplexed.
So confusing with transport format, transport format set ?
The fact: Several transport channels can be multiplexed in a single physical channel.
So, transport format combination (TFC) defines the number of transport blocks that are transmitted from each of the multiplexed transport channels in a given TTI.
Example:
DCH1:
{10ms, turbo coding, static rate matching parameter =1}
{40 bits, 40 bits}
DCH2:
{10ms, [...]
Transport format set is
a set of allowed transport formats for a given transport channel.
As a result, it limits the max number of transport blocks that can be transmitted in a TTI, or it limits the max instantaneous bit rate.
Example:
{10ms, turbo coding, static rate matching parameter =1}
{40 bits, 40 bits}; {40 bits, 80 bits}; {40 bits, [...]
Transport format defines the data in a transport block set and how it should be handled by the physical layer.
It consists two parts:
1. semistatic
TTI, error protection scheme, size of CRC, static rate matching parameter,
2. dynamic
transport block size, transport block set size
Example:
{10ms, turbo coding, static rate matching parameter =1}
{320 bits, 640 bits}
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Interesting point:
The number of transport [...]
Does the UE lose the entire TTI data or not ?
If you know the answer, I’ll appreciate if you let me know.
The MAC layer generates a new transport block every 10-ms (or multiple of blocks.)
A set of simultaneous transport blocks is the transport block set.
The transmission time interval (TTI) is the duration of each transport block set.
This can be 10, 20, 40, 80 ms.
TTI does not tell you data size. It tells you how often the [...]
