Adaptive asymmetric connections for TCP communications over the DECT air interface

This works aims at evaluating achievable performance for TCP/IP data transfer over DECT radio interface, by verifying the ability of DECT lower layers protocols, namely DLC and MAC, to mask the radio interface unreliability and to provide flexible transfer means for TCP data. Major points are: (i) the interplay of error recovery mechanisms at the various layers; (ii) the effectiveness of providing multibearer capabilities (i.e. allowing slot bundling in the radio access); (iii) the possible gains brought about by MAC asymmetric connections in view of essentially asymmetric TCP data flows. Obtained results indicate that satisfactory performance can be obtained, since the lower layers recovery functions are able to mask even a rather pessimistic radio channel behavior as here assumed. This comes at the price of about half of the gross available capacity, because of static overhead and radio channel impairments, which is anyway in the order of (often less than) typical overhead due to radio communication protecting codes, e.g., as defined in GSM, UMTS, CDPD.