e building block name is determined by the predominant usage of the block. 2 TMN building blocks may contain additional functionality which allows them to be managed. 3 For the WSF to be present either the MF or OSF must also be present. This means that the WSF must address an OSF or a MF. The local man-machine access is not considered part of the TMN. Source: ITU-R 1996 [25]. Next Generation Mobile Communications Ecosystem Table 8.3 TMN interfaces and reference points [3] TMN Reference TMN Interfaces TMN Interfaces Points It exists between NE and OS, os and OS, os and MF, and between QA and OS. It is the only interface that is used to communicate with os It carries information that is shared between the MF and NE, between MFs and between MF and QA It exists between a WS and os, and between a WS and MD It exists when each OSF is in different domain Note: Two other reference points, g and m, are outside the scope of TMN. They are between non-TMN entities and the non-TMN portion of the WSF and QAF, respectively. Network Element (NE) is comprised of telecommunication equipment (or groups/parts of telecom- munication equipment) and support equipment or any item or groups of items considered as belonging to the telecommunications environment that performs NEFs. The NE may optionally contain any of the other TMN function blocks according to its implementation requirements. The NE has one or more standard Q-type interface and may optionally have F and X interfaces. Workstation (WS) is the system which performs WS functions. The workstation functions translate information at the f reference point to a displayable format for the user at the g reference point, and vice versa. In order for two or more TMN building blocks to exchange management information they must be connected by a communications path and each element must support the same interface onto that communications path. The concept of an interoperable interface simplifies the communications problems arising from multi-vendor in multi-capability networks. The rela