Technical Product Manual - DCT1900Configuration Directions, Base Station PoweringConfig-DCT1900/R8/mw 4-1© 2000-2005CHAPTER 4Base Station Powering4.1 GeneralAfter a Base Station plan has been made (see Chapter 3), it must be established which poweringmethod is more suitable to power the Base Stations. The methods for powering a Base Station are:z Via the REz By a remote power supplyThe choice of the method depends upon:z The distance between the RE and the Base Stationsz The total number of Base Stationsz Whether power back–up is needed or notz Installation costsParagraph 4.2 describes the powering of Base Stations by means of a remote power supply.Paragraph 4.3 describes the powering options for the Modular Cabinet. The tables used in thischapter are given in Paragraph 4.4.The length limits for the Base Station cable are described below.Data Limited Length of the Base Station CableData transmission via twisted pairs is limited to a certain range. The "data limited" length of thecables between the RE and the Base Stations depends on the system board used (CLU or SLU),the characteristics of the cable, and the noise on the cable. Table 4–1 shows the data limitedlength for some cables.Note:Since it is not possible to predict the noise level in an environment and its influence on a cable, thevalues from the table should be taken as a guide-line more than a rule. Practically, the maximumlength may exceed these values, in case there is less noise and vice versa if there is more noise.Power Limited Length of Base Station CableWhen a Base Station is powered via the cabinet, the maximum length between the Base Stationand the RE depends on the supply voltage, the number of twisted pairs used and the wire size.The length of the cable should never exceed the "data–limited" length of the cable.4.2 Powering Base Stations by a Remote Power SupplyWhen Base Stations are powered by a remote power supply, only a cable with two twisted pairs isrequired between a Base Station and the RE for data transfer (see Figure 4–1).Powering Base Stations with a remote power supply can be done by using the EPP pins on theBase Station connector. Base Stations can be powered individually or in clusters from a centralpower source. A cluster can be e.g. Base Stations on the same floor or in the same building,assuming that Base Stations within the cluster are close enough to the remote power supply. Thelength of the cable between the Base Station and the RE is "data limited". See Table 4-1 for themaximum cable length.
