Abstract
In the medical field obtaining fast access to accurate patient information is a necessity. With the requirement of Electronic Medical Records, information technology plays an enormous role in the medical industry. Providing the correct network architecture, and infrastructure will allow hospitals to have up-to-date information about all its patients and personnel at all times, to avoid any serious mistakes that can determine the welfare of the patients.

Information Systems and Network Overview
The Patton-Fuller Community Hospital information technology infrastructure consists of two main areas; the clinical and administrative areas. The clinical areas are
• Emergency Rooms and Operating Rooms
• Pharmacy
• Labs
• Radiology
• Doctors personal offices
• Wards
• Outpatient examining rooms
• Intensive Care Units
The administrative function areas are
• Information Technology Department
• Admitting/Discharge
• Facilities
• Human Resources
• Hospital Senior Management
• Finance
Data transmission
The hospital uses a technology named Local Area Network (LAN) to transmit data/information within the hospital. The two main reasons to use this technology are for information sharing, and resource sharing. Information sharing allows users to access and modify the same data files, exchange information via e-mail, and use the Internet. One of the main benefits of information sharing is to improve the decision-making process, for example, doctors in different departments have access to the patient files immediately to make important on-the-spot decisions. Resource sharing refers to computers sharing different hardware devices as well as software to save the cost of the operation. For example, sharing one printer among a department instead of buying one printer per computer; the same applies to software.
The hospital uses a standard called Ethernet to connect and communicate the two LANs; administrative and clinical. Ethernet is a standard formalized by the Institute of Electrical and Electronics Engineers (IEEE) as IEEE 802.3, it is a layer two (Data Link Layer) protocol, which needs hardware at layer one (Physical Layer) to communicate. Ethernet is compatible with a variety of layer three (Network Layer) protocols but is most commonly used with Transmission Control Protocol/Internet Protocol (TCP/IP).
The Administrative Departments communicate internally via 1000Base-T (Ethernet Backbone) CAT6 cable, whereas the Clinical Departments use a 1000Base-F (Fiber Optic) standard. The Administrative Ethernet backbone consists of the use of cooper wires, “one of the most commonly used types of guided media which is the twisted-pair cable, insulated pairs of wires that can be packed quite close together. The wires usually are twisted to minimize the electromagnetic interference between one pair and any other pair in the bundle” (Fitzgerald & Dennis, 2009, p. 88). The 1000Base-T and the 1000Base-F run at a maximum data rate of 1Gbps (Gigabyte per second).
The Ethernet logical topology is a bus topology were the devices connect to one-half-duplex circuit running the length of the network. The frames from any computers flow onto the central cable (or bus) and through it to all computers on the LAN. Every computer on the bus receives all the frames sent on the bus, but before processing the incoming frames, the Ethernet software on each computer checks the data link layer address and processes only those frames addresses to that specific computer. This configuration creates latency on information dissemination across the network.
Clinical Local Area Network Details
The clinical area departments communicate via a 1000Base-F single mode fiber that according to Multicom (1999) “has a small diametric core that allows only one mode of light to propagate. Because of this, the number of light reflections created as the light passes through the core decreases, lowering attenuation and creating the ability for the signal to travel faster, further. This application is typically used in long distance, higher bandwidth” (Single Mode Fiber Optic Cable).
The Outpatient examining rooms, Intensive Care Unit and the Ward floor systems also have a Cisco 3500 Series 5GHz Wireless Access Point (at least one per ward, and per ICU area) that allows to connect MAC new iPads (32GB Wi-fi) wirelessly. Each patient room has one fiber optic network connection per bed, and each nurse workstation has a printer as well as a fiber connection.
Administrative Local Area Network Details
The administrative functions network communicates via a 1000Base-T CAT6 cable that connects all of its departments in a bus architecture. The Executive Management, Human Resources, Operations, and Finance Senior Manager Departments have an Apple iMac Workstations. All personnel involved in data entry in the human resources department, Operations, and Finance have a Hewlett Packard Model L1706 Thin Client computer.
The IT Data Center servers and workstations share the same network on a bus topology using 1000Base-T with CAT6 cable, and the IT Data Center backbone connects to a Network Bridge, which in turn, is connects to the 1000base-F fiber network from the hospital’s clinical department (University of Phoenix, 2006).
The Backbone Network
Both of these networks use a Backbone network (BN) to communicate. There are two basic components to a BN: the network cable, and the hardware devices that connect other networks. The network cable is basically the same cable used in the individual LANs, CAT5e, CAT6, and Fiber Optic cable. The hardware device that allows these networks to talk is a Network Bridge. The network bridge is a network device that connects multiple network segments.
The OSI Layers Involved
The Patton-Fuller Community Hospital uses a various layers of the OSI model in its network. The first one is physical layer, which it is the most basic layer of the OSI model, and it deals with the physical circuit itself, the cable, either copper, fiber, or wireless (radio frequency). Computers communicate with digital data, also known as binary, either on or off, one or zeros. In the case of copper (CAT6) deals with electrical pulses (electricity = 1, no electricity=0, while fiber optic cables uses light pulses (light = 1, no light = 0).
The second layer in use by the hospital’s network is the data link layer; it is responsible for sending and receiving messages to and from other computers. Its job is to move messages from one computer to another reliably. This particular layer consists of two sub-layers; the logical link layer (LLC) and the media access layer (MAC). The LLC communicates with the layer above (the Network layer) and deals with the Protocol Data Unit (PDU) –an IP Packets- to identify to which computer to send the message, while the MAC sub-layer controls the physical hardware in layer 1. The MAC layer controls how and when the physical layer converts bits into physical symbols that travel over the circuit. The method used in this layer is “a contention-based media access control technique called Carrier Sense Multiple Access with Collision Detection (CSMA/CD). CSMA/CD, like all contention-based techniques, is very simple in concept: wait until the circuit is free and then transmit. Computers wait until no other devices are transmitting, then transmit their frames” (Fitzgerald & Dennis, 2009, p. 211).
Recommendations
After analyzing the hospital network, one of its disadvantages is the network topology. A bus network topology (logical) uses one circuit as the backbone to connect all devices, meaning that if it fails, all of the devices will fail as well. The advantages with this topology are cost and are easy to administer or manage, but it has a single point of failure. Both LANs connect to a network bridge that if it fails will not allow computers from the two different networks to communicate, also providing a single point of failure. One of the most important concepts about networks is availability, and these topologies do not offer it.
The recommendation is to replace the networked bridge with a router, and installing a switch in every department to create a Routed Backbone Network. The router breaks the network into separate subnets. Message traffic stays within each subnet unless it specifically needs to leave the subnet to travel elsewhere on the network, in which case the Network Layer address is used to move the packet. A switch is an intelligent device with a small computer built-in designed to manage a set of separate point-to-point circuits. This means that each device connects to the switch, and the circuit is not shared across all the devices, providing higher bandwidth for all applications, and individual hardware devices. This network uses a star topology with the router in the center, while all the switches from the different departments connect to it. This topology’s performance is faster because it keeps all the broadcasts messages within the subnet, it will transmit to the router when it needs to leave the sub network. It also has all the network equipment in one place for easy maintenance, management, and upgrade.
This recommendation provides the most cost-efficient change to the network, without replacing the whole network infrastructure. By replacing the network bridge for a router that provides port speeds up to 1Gbps, provides a series of separate point-to-point circuits to the attached devices, so that no device needs to wait for another device before it transmits. A Switched Backbone Network has a considerably better performance than traditional Ethernet because computers do not have to share circuits with other computers.
The communication protocol used in this network is TCP/IP, because it provides accuracy on data transmission, which is the most important aspect about medical information. “TCP/IP allows reasonably efficient and error-free transmission. Because it performs error checking, it can send large files across sometimes unreliable networks with great assurance that the data will arrive uncorrupted” (Fitzgerald & Dennis, 2009, p. 150).

References
Fitzgerald, J., & Dennis, A. (2009). Business Data Communications and Networking (11th ed.). Hoboken, NJ: John Wiley & Sons Inc.
Multicom. (1999). Multicom. Retrieved from http://www.multicominc.com/active/manufacturer/multicom/Fiber%20Optics/singlemode-multimode.html University of Phoenix. (2006). Patton-Fuller Community Hospital Network Diagrams. Retrieved from University of Phoenix, CMGT554 - IT Infrastructure website.