TTI, Transmission Time Interval, is a parameter in UMTS (and other digital telecommunication networks) related to encapsulation of data from higher layers into frames for transmission on the radio link layer. TTI refers to the duration of a transmission on the radio link. The TTI is related to the size of the data blocks passed from the higher network layers to the radio link layer.
To combat errors due to fading and interference on the radio link, data is divided at the transmitter into blocks and then the bits within a block are encoded and interleaved. The length of time required to transmit one such block determines the TTI. At the receiver all bits from a given block must be received before they can be deinterleaved and decoded. Having decoded the bits the receiver can estimate the bit error rate (BER). And because the shortest decodable transmission is one TTI the shortest period over which BER can be estimated is also one TTI. Thus in networks with link adaptation techniques based on the estimated BER the shortest interval between reports of the estimated performance, which are used to adapt to the conditions on the link, is at least one TTI. In order to be able to adapt quickly to the changing conditions in the radio link a communications system must have shorter TTIs. In order to benefit more from the effect of interleaving and to increase the efficiency of error-correction and compression techniques a system must, in general, have longer TTIs. These two contradicting requirements determine the choice of the TTI.
In UMTS Release '99 the shortest TTI is 10 ms and can be 20 ms, 40 ms, or 80 ms. In UMTS Release-5 the TTI for HSDPA is reduced to 2ms. This provides the advantage of faster response to link conditions and allows the system to quickly schedule transmissions to mobiles which temporarily enjoy better than usual link conditions. As a result the system most of the time transmits data over links which are better than the average conditions, because of this the bit rates in the system most of the time are higher than what the average conditions would allow. This leads to increase in system capacity.
In 1xEV-DO technology, a slot, which is not quite the same thing as the TTI, but which still fulfills a somewhat similar function, is 1.667 ms. In 1xEV-DV it has a variable length of 1.25 ms, 2.5 ms, 5 ms, and 10 ms.
and 27 Related for: Transmission Time Interval information
TTI, TransmissionTimeInterval, is a parameter in UMTS (and other digital telecommunication networks) related to encapsulation of data from higher layers...
light for the same timeinterval, positive intervals are always timelike. If s 2 {\displaystyle s^{2}} is negative, the spacetime interval is said to be spacelike...
events or the intervals between them, and to quantify rates of change of quantities in material reality or in the conscious experience. Time is often referred...
during a significant measurement timeinterval divided by (b) the measurement timeinterval. The effective transmission rate is usually expressed as a number...
agency Texas Tennessee Industries, now Igloo Products Corporation TransmissionTimeInterval in digital telecommunication Toyota Technological Institute, Japan...
The serial interval in the epidemiology of communicable (infectious) diseases is the time between successive cases in a chain of transmission. The serial...
channel transmission, and its key features are shared channel and multi-code transmission, higher-order modulation, short TransmissionTimeInterval (TTI)...
of an asynchronous transmission. The intercharacter interval may be of any duration. The signal sense of the intercharacter interval is always the same...
individual characters. An example of a timeinterval that is excluded when determining character interval is any time added between the end of a stop signal...
guard intervals are used to ensure that distinct transmissions do not interfere with one another, or otherwise cause overlapping transmissions. These...
exact timeinterval elapsed between two UTC timestamps without consulting a table showing how many leap seconds occurred during that interval. By extension...
EDGE in a number of ways. Latencies are reduced by lowering the TransmissionTimeInterval by half (from 20 ms to 10 ms). Bit rates are increased up to 1 Mbit/s...
Shift time refers to the timeinterval between gear changes in a transmission. This interval is the time in which power delivery is transferred to the...
pertaining to transmission in which the timeinterval separating any two corresponding transitions is not necessarily related to the timeinterval separating...
the time it takes each packet to arrive, δ, is the emission interval for cells at the PCR TPCR, and the emission interval, T, is the emission interval for...
milliseconds – the timeinterval between gear changes on a Lamborghini Aventador; with a 7-speed single-clutch automated manual transmission 50 milliseconds...
raster scan display, the vertical blanking interval (VBI), also known as the vertical interval or VBLANK, is the time between the end of the final visible line...
to data transmission is called Radio Bearer (RB). This set of properties decides the maximum allowed data in a TTI (TransmissionTimeInterval). RB includes...
differs from transmission manufacturer to transmission manufacturer. Always consult the vehicle maintenance guide for the proper service interval for the fluid...
phenomenon of variation in the timeinterval between heartbeats. It is measured by the variation in the beat-to-beat interval. Other terms used include "cycle...
unit time. The bit error ratio (also BER) is the number of bit errors divided by the total number of transferred bits during a studied timeinterval. Bit...
An interval signal, or tuning signal, is a characteristic sound or musical phrase used in international broadcasting, numbers stations, and by some domestic...
Poacher" Recording of the E03 "Lincolnshire Poacher" interval signal, followed by a coded transmission of five numbers, 0-2-5-8-8. Problems playing this...
replacement-in-place of existing transmission lines with higher capacity lines. Adding transmission lines is difficult due to cost, permit intervals, and local opposition...
senders in a conference to report transmission and reception statistics for all RTP packets sent during the interval. The sender report includes two distinct...
also occur in a computer network where data transmission is interrupted at intervals. Burst transmission enables communications between data terminal...
of events is isochronous if the events occur regularly, or at equal timeintervals. The term isochronous is used in several technical contexts, but usually...
Global Information