wledged. Once the handoff is complete, the target sends a message to release the facility, and that message is acknowledged. A path minimization is seven or more messages. The serving MSC sends a message to the anchor MSC that may go through one or more tandem MSCs. The serving MSC communicates directly with the target MSC using two messages to establish a connec- tion for the handoff and then acknowledges the path-minimized handoff to the serving Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. ANSI-41 Signaling Capacity Capacity and Quality Principles MSC. Once the handoff is complete, the serving MSC and anchor MSC coordinate the release of their facility with two messages that may go through the same tandem MSCs. When a handed-off call is released while the serving MSC is not the anchor MSC, the call release is two messages, one to release the facility and one to acknowledge. Each tandem MSC adds two messages to the tally. 25.1.1 Total handoff message count What does this tell us about inter-MSC handoff signaling? It gives us an idea of how much inter-MSC signaling to expect from handoff traffic. If we can estimate the hand- off activity, then we can add up the messages to estimate the signaling load. The number of handoff measurements is related to the number of calls in border sec- tors. We can think of each call as having some likelihood of having a handoff measure- ment involving another MSC or more than one other MSC. By knowing the call volume and the rate of handoff measurements per call minute, we can estimate the number of handoff measurements. We also know that each estimate has one to two messages per neighboring MSC, so this gives us an MSC-to-MSC message load from handoff measurements. The first inter-MSC handoff of any call is a handoff forward with three inter-MSC messages. Subsequent handoffs are not so predictable, but th