Mixed and Absolute Cell References. To avoid this problem created by the relative cell reference A7, mixed and absolute cell references can be used, which prevent all or part of a cell reference in a formula from changing as it is copied. Absolute and mixed cell references are created by adding dollar signs ($) to a cell reference. For example, in the image above, the cell reference $A$6 in the formula in cell B2 is an absolute cell reference and $A2 is a mixed cell reference.
The point of sale (POS) is the time and place where a retail transaction is completed. It is the point at which a customer makes a payment to the merchant in exchange for goods or after provision of a service.
The typical PON arrangement is a point to multi-point (P2MP) network where a central optical line terminal (OLT) at the service providerâs facility distributes TV or Internet service to as many as 16 to 128 customers per fiber line (see the figure) .PON does not use the CSMA/CD access method used in other versions of Ethernet. Since Ethernet is the primary networking technology used in local-area networks (LANs) and now in metro-area networks (MANs), no protocol conversion is needed.