On the Reverse Link Capacity of a CDMA Network of Femto-cells

Femto-cells are currently being considered by several wireless operators as an attractive, scalable solution to improve coverage and user experience in residential and enterprise deployments. Such deployments, when co-existent with macro-cellular carriers, are also expected to help alleviate the increasing load on these macro-carriers and therefore improve user experience in the macro-network too. Several wireless vendors are already in the process of developing Femto-cell base-transceiver-stations (BTSs) based on 3G technologies such as WCDMA and EVDO. In this paper we present some results on the reverse link (RL) capacity of a CDMA network of Femto-cells, where we assume that the Femto-BTSs do not "cooperate" with each other, i.e., each Femto-BTS communicates with its own users (for e.g., different access terminals in a house that installed a Femto-BTS) and these users do not go into RL soft-handoff with another Femto-BTS (for e.g., the Femto-BTS of the neighboring house). There are other differences that we will highlight between the Femto CDMA network and the macro 3G CDMA cellular network, which play an important role in our analysis. This analysis is quite suitable for a basic CDMA-based Femto-cell voice network, and needs some modifications to account for enhanced reverse link rate control mechanisms such as the RTCMAC algorithm in EVDO Rev. A.