Hot-spot traffic relief with a tilted antenna in CDMA cellular networks

Direct-sequence code-division multiple-access (DS-CDMA) cellular networks are highly promising in terms of their potential to provide more capacity than an advanced mobile phone system (AMPS), However, heterogeneous traffic loading causes traffic congestion in a CDMA hot spot, This paper presents a tilted-antenna mechanism for sectored cells in CDMA cellular networks to relieve the congestion in a hot-spot sector, The fixed antenna-tilted mechanism, which only tilts the hot-spot antenna, can provide the merit of traffic balancing, Besides, we design a dynamic antenna-tilted mechanism in which tilting the antennas of the hot spot and its adjacent cell sectors is based on varying the signal-to-noise ratio (SNR), The dynamic mechanism can automatically tilt the antenna corresponding to the variation of traffic, Consequently, more capacity can be provided than in fixed tilting mechanism, which only tilts the hot-spot antenna, Another benefit is the traffic-balancing effect with a tilted-antenna mechanism that reduces the transceivers of hot-spot base station, Therefore, extra facilities are unnecessary for the hot spot than for a normal or light traffic sector.