Abogados (DCH) (Lawyers (DCH))

The DCH Hash Function

The DCH algorithm is a byte-oriented, endian-neutral, block-cipher-based hash function. It generally follows the Merkle-Damg̊ard structure [4] [11], and compression is performed via Miyaguchi-Preneel iteration [13] on successive message blocks. Each message block consists of 504 bits (63 bytes); the block is then preprocessed to form a 512-bit input to the compression function. The algorithm use...

Notes for the DCH.

How to pass the DCH.

Having both failed and passed the DCH examination in the past 12 months, I feel able to offer a few words of advice to prospective candidates. It is useful to have a broad idea of the nature of the examination. It is not a test to be taken after a casual browse through a friend's textbook. It is a demanding diploma which, for that reason alone, may be rewarding for the well-prepared. There is a...

Performance of UMTS packet service over dedicated channels (DCH)

The provision of high speed packet data services in an efficient way is probably the most important challenge for the Universal Mobile Telecommunications System (UMTS) since this can give an advantage over second generation systems. The efficiency depends mainly on the radio interface due to its great flexibility. It is of utmost importance to investigate the effect of different configurations ...

Improving the Performance of DCH Timing Adjustment in 3G Networks

The main goal of Transport Channel Synchronization is that frames sent by the RNC arrive in time to the Nodes B for transmission over the air interface. The 3GPP specifies a simple Timing Adjustment algorithm that tracks the delay of the Iub link (interface defined between RNC and Node B) by adding or subtracting a constant step. We show that this scheme reacts too slowly under abrupt delay var...