  We propose a quantum computer architecture based on quantum dots both for
short distance and for long distance communication/computation. Our scheme
exploits the natural characteristics of self-assembled quantum dots and it is
scalable. It is centered on the idea of a quantum bus based on semiconductor
self-assembled quantum dots. This allows for transmission of qubits between the
different quantum registers, and could be integrated in most of the present
proposal for semiconductor quantum dot-based quantum computation. Our proposal
exploits the peculiar properties of {\it relatively short} spin-chains, and
advantages and disadvantages of two possible implementations, both based on
spin-chain global dynamics, are discussed in details. A clear advantage of the
scheme is to avoid the use of microcavities for long distance communication
between different elements of the quantum computer. In this respect our scheme
is comparatively faster than hybrid quantum dot-microcavity schemes.
