An efficient residential LTE small cell using a “designated” wireless local loop band

Abstract

Mobile Network Operators (MNOs) as well as Fixed Network Operators (FNOs) are actively searching for solutions to satisfy the exponentially growing users' demand for broadband services, such as high definition video content and real time applications, at a reasonable CAPEX investment. At the same time, MNOs have to deal with the scarcity and expensiveness of the new “licensed” radio bands, and FNOs have to deal with the high congestion of the current “unlicensed” radio bands such as the Industrial, Scientific and Medical (ISM) radio band. However, some of the Wireless Local Loop (WLL) radio bands, such as the DECT band (1880/1900 MHz), due to their “designated” band status, attributed by the competent regulator entities, are much less congested. In this paper, we propose to re-engineer the Customer Premises Equipment (CPE) that FNOs provide to the end user, so that it continues to offer the traditional short-range Cordless Telephony service to a few DECT handsets but at the same time introduces a new residential Long Term Evolution (LTE) small cell service, operating as an “underlay” application in the same “designated” DECT band, for the broadband hungry devices. We do not modify the WiFi service that is also included in the CPE. We are aware that the deployment of our proposal might require a revision of the “designation” of the DECT band by the Electronic Communications Committee (ECC). The CPE we propose is capable to dynamically adjust the assignment of the radio resource, with a 2 MHz granularity, to the Cordless Telephony service and the new LTE small cell service, as a function of the user's DECT service needs. Under some conditions the whole DECT band could be used to provide exclusively DECT services, as in the case of the current situation, and under some other conditions, the DECT band could be used to share it between the DECT service that has the highest priority and the new LTE small cell service. We believe that a configuration where the DECT service has the warranted capability to simultaneously offer the Cordless Telephony service to 12 DECT handsets should be suitable in most of the cases. In this situation, only 2 MHz bandwidth is enough to transport the audio conversations with high quality, and therefore, the remaining 18 MHz can be assigned for the residential LTE small cell that could provide user data rates from 45 Mbps to 450 Mbps to the customer applications.