Heart is established by the sinoatrial node, the heart's pacemaker. Here an electrical signal is created that travels through the heart, causing the heart muscle to contract. The sinoatrial node is found in the upper part of the right atrium near to the junction with the superior vena cava. The electrical signal generated by the sinoatrial node travels through the right atrium in a radial way that is not completely understood. It travels to the left atrium via Bachmann's bundle, such that the muscles of the left and right atria contract together. The signal then travels to the atrioventricular node. This
Node B frequency transmitter(s) and the receiver(s) used to communicate directly with mobile devices, which move freely around it. In this type of cellular network, the mobile devices cannot communicate directly with each other but have to communicate with the NodeB. Traditionally, the Node Bs have minimum functionality, and are controlled by an RNC (Radio Network Controller). However, this is changing with the emergence of High Speed Downlink Packet Access (HSDPA), where some logic (e.g., retransmission) is handled on the Node B for lower response times. The utilization of WCDMA technology allows cells belonging to the same or different Node Bs and