How Hybrid Networks Work:
Wires are for work. Wireless is for play. A few years ago, that was the conventional wisdom on wired versus wireless networks. Wi-Fi was great for checking e-mail at Starbucks, but it wasn’t fast enough or secures enough for an office setting — even a home office. For speed and security, Ethernet cables were the only way to go.
Things are changing. Now people are viewing Ethernet and Wi-Fi as important components of the same local area network (LAN). Wires are great for linking servers and desktop computers, but Wi-Fi is ideal for extending that network seamlessly into the conference room, the lunch room, and yes, evens the bathroom.
Think about the typical college or university LAN. According to a 2007 survey, 73.7 percent of college students own a laptop [source: Educause Center for Applied Research]. And they expect to be able to access the Internet and share files across the college network, whether they’re in the physics lab or sunbathing in the quad. That’s the role of a hybrid network.
A hybrid network refers to any computer network that contains two or more different communications standards. In this case, the hybrid network uses both Ethernet (802.3) and Wi-Fi (802.11 a/b/g) standards. A hybrid network relies on special hybrid routers, hubs and switches to connect both wired and wireless computers and other network-enabled devices.
How do you set up a hybrid network? Are hybrid routers expensive? Is it hard to configure a Wi-Fi laptop to join an existing wired network? Read on to find out more about hybrid networks.
Understanding Hybrid Networks:
In a wired computer network, all devices need to be connected by physical cable. A typical configuration uses a central access point. In networking terms, this is called a star topology, where information must travel through the center to reach other points of the star.
The central access point in a wired network can be a router, hub or a switch. The access point’s function is to share a network connection among several devices. All the devices are plugged into the access point using individual Ethernet (CAT 5) cables. If the devices want to share an Internet connection as well, then the access point needs to be plugged into a broadband Internet modem, either cable or DSL.
In a standard wireless network, all networked devices communicate with a central wireless access point. The devices themselves need to contain wireless modems or cards that conform with one or more Wi-Fi standards, either 802.11 a, b or g. In this configuration, all wireless devices can share files with each other over the network. If they also want to share an Internet connection, then the wireless access point needs to be plugged into a broadband modem.
A standard hybrid network uses something called a hybrid access point, a networking device that both broadcasts a wireless signal and contains wired access ports. The most common hybrid access point is a hybrid router. The typical hybrid router broadcasts a Wi-Fi signal using 802.11 a, b or g and contains four Ethernet ports for connecting wired devices. The hybrid router also has a port for connecting to a cable or DSL modem via Ethernet cable.
When shopping for a hybrid router, you might not see the word “hybrid” anywhere. You’re more likely to see the router advertised as a wireless or Wi-Fi router with Ethernet ports or “LAN ports” [source: About.com]. Hybrid routers start at around $50 for a basic model with four Ethernet ports and a network speed of 54Mbps (megabits per second).
There are several different possible network configurations for a hybrid network. The most basic configuration has all the wired devices plugged into the Ethernet ports of the hybrid router. Then the wireless devices communicate with the wired devices via the wireless router.
But maybe you want to network more than four wired devices. In that case, you could string several routers together; both wired and wireless, in a daisy chain formation. You’d need enough wired routers to handle all of the wired devices (number of devices divided by four) and enough wireless routers — in the right physical locations — to broadcast a Wi-Fi signal to every corner of the network.
Computers aren’t the only devices that can be linked over a hybrid network. You can now buy both wired and wireless peripheral devices like printers, Web cams and fax machines. An office worker with a laptop, for example, can print a document without plugging directly into the printer. He can send the document over the hybrid network to the networked printer of his choice.
Now let’s look at the advantages and disadvantages of traditional wired and wireless networks and how hybrid networks offer the best of both worlds.
Hybrid Networks: Wired vs. Wireless
The chief advantage of a wired network is speed. So-called “Fast Ethernet” cables can send data at 100Mbps while most Wi-Fi networks max out at 54Mpbs [source: About.com]. So if you want to set up a LAN gaming party or share large files in an office environment, it’s better to stick with wired connections for optimum speed. Take note, however, that the upcoming 802.11n Wi-Fi standard claims throughput speeds of 150 to 300Mbps [source: Network World].
The chief advantage of a wireless network is mobility and flexibility. You can be anywhere in the office and access the Internet and any files on the LAN. You can also use a wider selection of devices to access the network, like Wi-Fi-enabled handhelds and Pads.
Another advantage of wireless networks is that they’re comparatively cheaper to set up, especially in a large office or college environment. Ethernet cables and routers are expensive. So is drilling through walls and running cable through ceilings. A few well-placed wireless access points — or even better, a wireless mesh network — can reach far more devices with far less money.
Other than that, both wired and wireless networks are equally easy (or difficult) to set up, depending on the organization’s size and complexity. For a small office or home network, the most popular operating systems — Windows XP, Vista and Mac OS 10 — can guide you through the process with a networking wizard. Installing and administering a large office or organizational network is equally tricky whether you’re using wired or wireless. Although with wireless connections, you don’t have to go around checking physical Ethernet connections.
As for security, wired is generally viewed as more secure, since someone would have to physically hack into your network. With wireless, there’s always a chance that a hacker could use packet-sniffing software to spy on information traveling over your wireless network. But with new wireless encryption standards like WEP (Wired Equivalent Privacy) and WPA (Wi-Fi Protected Access) built into most Wi-Fi routers, wireless networking is nearly as secure as wired.
A hybrid wired/Wi-Fi network would seem to offer the best of both worlds in terms of speed, mobility, affordability and security. If a user needs maximum Internet and file-sharing speed, then he can plug into the network with an Ethernet cable. If he needs to show a streaming video to his buddy in the hallway, he can access the network wirelessly. With the right planning, an organization can save money on CAT 5 cable and routers by maximizing the reach of the wireless network. And with the right encryption and password management in place, the wireless portion of the network can be just as secure as the wired.
Network topology is the layout pattern of interconnections of the various elements (links, nodes, etc.) of a computer<href=”#cite_note-Groth-0><href=”#cite_note-atis-1> or biological network.<href=”#cite_note-Proulx05-2> Network topologies may be physical or logical. Physical topology refers to the physical design of a network including the devices, location and cable installation. Logical topology refers to how data is actually transferred in a network as opposed to its physical design. In general physical topology relates to a core network whereas logical topology relates to basic network.
Topology can be understood as the shape or structure of a network. This shape does not necessarily correspond to the actual physical design of the devices on the computer network. The computers on a home network can be arranged in a circle but it does not necessarily mean that it represents a ring topology.
Any particular network topology is determined only by the graphical mapping of the configuration of physical and/or logical connections between nodes. The study of network topology uses graph theory. Distances between nodes, physical interconnections, transmission rates, and/or signal types may differ in two networks and yet their topologies may be identical.
A local area network (LAN) is one example of a network that exhibits both a physical topology and a logical topology. Any given node in the LAN has one or more links to one or more nodes in the network and the mapping of these links and nodes in a graph results in a geometric shape that may be used to describe the physical topology of the network. Likewise, the mapping of the data flow between the nodes in the network determines the logical topology of the network. The physical and logical topologies may or may not be identical in any particular network.
There are two basic categories of network topologies: <href=”#cite_note-Inc.2C_S._2002-3> 1 Physical topologies 2 Logical topologies
The shape of the cabling layout used to link devices is called the physical topology of the network. This refers to the layout of cabling, the locations of nodes, and the interconnections between the nodes and the cabling.<href=”#cite_note-Groth-0> The physical topology of a network is determined by the capabilities of the network access devices and media, the level of control or fault tolerance desired, and the cost associated with cabling or telecommunications circuits.
The logical topology, in contrast, is the way that the signals act on the network media, or the way that the data passes through the network from one device to the next without regard to the physical interconnection of the devices. A network’s logical topology is not necessarily the same as its physical topology. For example, the original twisted pair Ethernet using repeater hubs was a logical bus topology with a physical star topology layout. Token Ring is a logical ring topology, but is wired a physical star from the Media Access Unit.
The logical classification of network topologies generally follows the same classifications as those in the physical classifications of network topologies but describes the path that the data takes between nodes being used as opposed to the actual physical connections between nodes. The logical topologies are generally determined by network protocols as opposed to being determined by the physical layout of cables, wires, and network devices or by the flow of the electrical signals, although in many cases the paths that the electrical signals take between nodes may closely match the logical flow of data, hence the convention of using the terms logical topology and signal topology interchangeably.
Logical topologies are often closely associated with Media Access Control methods and protocols. Logical topologies are able to be dynamically reconfigured by special types of equipment such as routers and switches.
The study of network topology recognizes eight basic topologies: <href=”#cite_note-Bicsi.2C_B._2002-4>
- Ring or circular
- Daisy chain
The simplest topology is a permanent link between two endpoints. Switched point-to-point topologies are the basic model of conventional telephony. The value of a permanent point-to-point network is unimpeded communications between the two endpoints. The value of an on-demand point-to-point connection is proportional to the number of potential pairs of subscribers, and has been expressed as Metcalfe’s Law.
Easiest to understand, of the variations of point-to-point topology, is a point-to-point communications channel that appears, to the user, to be permanently associated with the two endpoints. A children’s tin can telephone is one example of a physical dedicated channel.
Within many switched telecommunications systems, it is possible to establish a permanent circuit. One example might be a telephone in the lobby of a public building, which is programmed to ring only the number of a telephone dispatcher. “Nailing down” a switched connection saves the cost of running a physical circuit between the two points. The resources in such a connection can be released when no longer needed, for example, a television circuit from a parade route back to the studio.
Main article: Bus network
Bus network topology
In local area networks where bus topology is used, each node is connected to a single cable. Each computer or server is connected to the single bus cable. A signal from the source travels in both directions to all machines connected on the bus cable until it finds the intended recipient. If the machine address does not match the intended address for the data, the machine ignores the data. Alternatively, if the data matches the machine address, the data is accepted. Since the bus topology consists of only one wire, it is rather inexpensive to implement when compared to other topologies. However, the low cost of implementing the technology is offset by the high cost of managing the network. Additionally, since only one cable is utilized, it can be the single point of failure. If the network cable is terminated on both ends and when without termination data transfer stop and when cable breaks, the entire network will be down.
The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has exactly two endpoints (this is the ‘bus’, which is also commonly referred to as the backbone, or trunk) – all data that is transmitted between nodes in the network is transmitted over this common transmission medium and is able to be received by all nodes in the network simultaneously.<href=”#cite_note-Groth-0>
Note: The two endpoints of the common transmission medium are normally terminated with a device called a terminator that exhibits the characteristic impedance of the transmission medium and which dissipates or absorbs the energy that remains in the signal to prevent the signal from being reflected or propagated back onto the transmission medium in the opposite direction, which would cause interference with and degradation of the signals on the transmission medium.
The type of network topology in which all of the nodes of the network are connected to a common transmission medium which has more than two endpoints that are created by adding branches to the main section of the transmission medium – the physical distributed bus topology functions in exactly the same fashion as the physical linear bus topology (i.e., all nodes share a common transmission medium).
1. All of the endpoints of the common transmission medium are normally terminated using 50 ohm resistor.
2. The linear bus topology is sometimes considered to be a special case of the distributed bus topology – i.e., a distributed bus with no branching segments.
3. The physical distributed bus topology is sometimes incorrectly referred to as a physical tree topology – however, although the physical distributed bus topology resembles the physical tree topology, it differs from the physical tree topology in that there is no central node to which any other nodes are connected, since this hierarchical functionality is replaced by the common bus.
Main article: Star network
Star network topology
In local area networks with a star topology, each network host is connected to a central hub with a point-to-point connection. The network does not necessarily have to resemble a star to be classified as a star network, but all of the nodes on the network must be connected to one central device. All traffic that traverses the network passes through the central hub. The hub acts as a signal repeater. The star topology is considered the easiest topology to design and implement. An advantage of the star topology is the simplicity of adding additional nodes. The primary disadvantage of the star topology is that the hub represents a single point of failure. However, according to O’Brien and Marakas, 2011, multiprocessor architecture has been commonly used as a solution to combat this disadvantage.<href=”#cite_note-5>
1. A point-to-point link (described above) is sometimes categorized as a special instance of the physical star topology – therefore, the simplest type of network that is based upon the physical star topology would consist of one node with a single point-to-point link to a second node, the choice of which node is the ‘hub’ and which node is the ‘spoke’ being arbitrary.<href=”#cite_note-Groth-0>
2. After the special case of the point-to-point link, as in note (1) above, the next simplest type of network that is based upon the physical star topology would consist of one central node – the ‘hub’ – with two separate point-to-point links to two peripheral nodes – the ‘spokes’.
3. Although most networks that are based upon the physical star topology are commonly implemented using a special device such as a hub or switch as the central node (i.e., the ‘hub’ of the star), it is also possible to implement a network that is based upon the physical star topology using a computer or even a simple common connection point as the ‘hub’ or central node.
4. Star networks may also be described as either broadcast multi-access or no broadcast multi-access (NBMA), depending on whether the technology of the network either automatically propagates a signal at the hub to all spokes, or only addresses individual spokes with each communication.
A type of network topology in which a network that is based upon the physical star topology has one or more repeaters between the central node (the ‘hub’ of the star) and the peripheral or ‘spoke’ nodes, the repeaters being used to extend the maximum transmission distance of the point-to-point links between the central node and the peripheral nodes beyond that which is supported by the transmitter power of the central node or beyond that which is supported by the standard upon which the physical layer of the physical star network is based.
If the repeaters in a network that is based upon the physical extended star topology are replaced with hubs or switches, then a hybrid network topology is created that is referred to as a physical hierarchical star topology, although some texts make no distinction between the two topologies.
A type of network topology that is composed of individual networks that are based upon the physical star topology connected in a linear fashion – i.e., ‘daisy-chained’ – with no central or top level connection point (e.g., two or more ‘stacked’ hubs, along with their associated star connected nodes or ‘spokes’).
Main article: Ring network
Ring network topology
A network topology that is set up in a circular fashion in which data travels around the ring in one direction and each device on the right acts as a repeater to keep the signal strong as it travels. Each device incorporates a receiver for the incoming signal and a transmitter to send the data on to the next device in the ring. The network is dependent on the ability of the signal to travel around the ring.<href=”#cite_note-Inc.2C_S._2002-3>
Main article: Mesh networking
The value of fully meshed networks is proportional to the exponent of the number of subscribers, assuming that communicating groups of any two endpoints, up to and including all the endpoints, is approximated by Reed’s Law.
Fully connected mesh topology
The number of connections in a full mesh = n (n – 1) / 2.
Note: The physical fully connected mesh topology is generally too costly and complex for practical networks, although the topology is used when there are only a small number of nodes to be interconnected (see combinatorial explosion).
Partially connected mesh topology
The type of network topology in which some of the nodes of the network are connected to more than one other node in the network with a point-to-point link – this makes it possible to take advantage of some of the redundancy that is provided by a physical fully connected mesh topology without the expense and complexity required for a connection between every node in the network.
Note: In most practical networks that are based upon the partially connected mesh topology, all of the data that is transmitted between nodes in the network takes the shortest path between nodes, except in the case of a failure or break in one of the links, in which case the data takes an alternative path to the destination. This requires that the nodes of the network possess some type of logical ‘routing’ algorithm to determine the correct path to use at any particular time.
Tree network topology
The type of network topology in which a central ‘root’ node (the top level of the hierarchy) is connected to one or more other nodes that are one level lower in the hierarchy (i.e., the second level) with a point-to-point link between each of the second level nodes and the top level central ‘root’ node, while each of the second level nodes that are connected to the top level central ‘root’ node will also have one or more other nodes that are one level lower in the hierarchy (i.e., the third level) connected to it, also with a point-to-point link, the top level central ‘root’ node being the only node that has no other node above it in the hierarchy (The hierarchy of the tree is symmetrical.) Each node in the network having a specific fixed number, of nodes connected to it at the next lower level in the hierarchy, the number, being referred to as the ‘branching factor’ of the hierarchical tree. This tree has individual peripheral nodes.
1. A network that is based upon the physical hierarchical topology must have at least three levels in the hierarchy of the tree, since a network with a central ‘root’ node and only one hierarchical level below it would exhibit the physical topology of a star.
2. A network that is based upon the physical hierarchical topology and with a branching factor of 1 would be classified as a physical linear topology.
3. The branching factor, f, is independent of the total number of nodes in the network and, therefore, if the nodes in the network require ports for connection to other nodes the total number of ports per node may be kept low even though the total number of nodes is large – this makes the effect of the cost of adding ports to each node totally dependent upon the branching factor and may therefore be kept as low as required without any effect upon the total number of nodes that are possible.
4. The total number of point-to-point links in a network that is based upon the physical hierarchical topology will be one less than the total number of nodes in the network.
5. If the nodes in a network that is based upon the physical hierarchical topology are required to perform any processing upon the data that is transmitted between nodes in the network, the nodes that are at higher levels in the hierarchy will be required to perform more processing operations on behalf of other nodes than the nodes that are lower in the hierarchy. Such a type of network topology is very useful and highly recommended.
Definition: Tree topology is a combination of Bus and Star topology.
Hybrid networks use a combination of any two or more topologies in such a way that the resulting network does not exhibit one of the standard topologies (e.g., bus, star, ring, etc.). For example, a tree network connected to a tree network is still a tree network topology. A hybrid topology is always produced when two different basic network topologies are connected. Two common examples for Hybrid network are: starring network and star bus network
- A Starring network consists of two or more star topologies connected using a multistation access unit (MAU) as a centralized hub.
- A Star Bus network consists of two or more star topologies connected using a bus trunk (the bus trunk serves as the network’s backbone).
While grid and torus networks have found popularity in high-performance computing applications, some systems have used genetic algorithms to design custom networks that have the fewest possible hops in between different nodes. Some of the resulting layouts are nearly incomprehensible, although they function quite well. [Citation needed]
A Snowflake topology is really a “Star of Stars” network, so it exhibits characteristics of a hybrid network topology but is not composed of two different basic network topologies being connected. Definition: Hybrid topology is a combination of Bus, Star and ring topology.
Except for star-based networks, the easiest way to add more computers into a network is by daisy-chaining, or connecting each computer in series to the next. If a message is intended for a computer partway down the line, each system bounces it along in sequence until it reaches the destination. A daisy-chained network can take two basic forms: linear and ring.
- A linear topology puts a two-way link between one computer and the next. However, this was expensive in the early days of computing, since each computer (except for the ones at each end) required two receivers and two transmitters.
- By connecting the computers at each end, a ring topology can be formed. An advantage of the ring is that the number of transmitters and receivers can be cut in half, since a message will eventually loop all of the way around. When a node sends a message, the message is processed by each computer in the ring. If a computer is not the destination node, it will pass the message to the next node, until the message arrives at its destination. If the message is not accepted by any node on the network, it will travel around the entire ring and return to the sender. This potentially results in a doubling of travel time for data.
The star topology reduces the probability of a network failure by connecting all of the peripheral nodes (computers, etc.) to a central node. When the physical star topology is applied to a logical bus network such as Ethernet, this central node (traditionally a hub) rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the remaining peripheral nodes will be unaffected. However, the disadvantage is that the failure of the central node will cause the failure of all of the peripheral nodes also,
If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way round trip transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.
A tree topology (a.k.a. hierarchical topology) can be viewed as a collection of star networks arranged in a hierarchy. This tree has individual peripheral nodes (e.g. leaves) which are required to transmit to and receive from one other node only and are not required to act as repeaters or regenerators. Unlike the star network, the functionality of the central node may be distributed.
As in the conventional star network, individual nodes may thus still be isolated from the network by a single-point failure of a transmission path to the node. If a link connecting a leaf fails, that leaf is isolated; if a connection to a non-leaf node fails, an entire section of the network becomes isolated from the rest.
To alleviate the amount of network traffic that comes from broadcasting all signals to all nodes, more advanced central nodes were developed that are able to keep track of the identities of the nodes that are connected to the network. These network switches will “learn” the layout of the network by “listening” on each port during normal data transmission, examining the data packets and recording the address/identifier of each connected node and which port it is connected to in a lookup table held in memory. This lookup table then allows future transmissions to be forwarded to the intended destination only.
In a mesh topology (i.e., a <href=”#Partial_mesh>partially connected mesh topology), there are at least two nodes with two or more paths between them to provide redundant paths to be used in case the link providing one of the paths fails. This decentralization is often used to advantage to compensate for the single-point-failure disadvantage that is present when using a single device as a central node (e.g., in star and tree networks). A special kind of mesh, limiting the number of hops between two nodes, is a hypercube. The number of arbitrary forks in mesh networks makes them more difficult to design and implement, but their decentralized nature makes them very useful. This is similar in some ways to a grid network, where a linear or ring topology is used to connect systems in multiple directions. A multi-dimensional ring has a steroidal topology, for instance.
A fully connected network, complete topology or <href=”#Full_mesh>full mesh topology is a network topology in which there is a direct link between all pairs of nodes. In a fully connected network with n nodes, there are n (n-1)/2 direct links. Networks designed with this topology are usually very expensive to set up, but provide a high degree of reliability due to the multiple paths for data that are provided by the large number of redundant links between nodes. This topology is mostly seen in military applications.
Wireless Routers Support Hybrid Networks:
A hybrid network is a local area network (LAN) containing a mix of both wired and wireless client devices. In home networks, wired computers and other devices generally connect with Ethernet cables, while wireless devices normally use Wife technology. Consumer wireless routers obviously support Wife clients, but do they also support the wired Ethernet ones? If so, how?
Answer: Most (but not all) consumer WiFi wireless routers support hybrid networks that include Ethernet clients. Traditional broadband routers that lack WiFi capability, however, do not.
To verify whether a particular model of wireless router supports a hybrid network, look for the following specifications on these products:
- “10/100 Ethernet ports” or
- “N-port Ethernet switch” (where N is a number such as “4” or “5”) or
- “wired LAN ports”
A mention of any of the above specs (and slight variations on these) indicate hybrid network capability.
The majority of hybrid network routers allow connection of up to four (4) wired devices. These can be 4 computers or any combination of computers and other Ethernet devices. Connecting an Ethernet hub to one of the router’s ports allow more than 4 wired devices to be joined to the LAN through the method of daisy chaining.
Finally, note that wireless routers offering only one Ethernet port are generally incapable of hybrid networking. This one port will typically be reserved for use by the broadband modem and connection to the wide area network (WAN).
Wired vs Wireless Networking:
Computer networks for the home and small business can be built using either wired or wireless technology. Wired Ethernet has been the traditional choice in homes, but Wi-Fi wireless technologies are gaining ground fast. Both wired and wireless can claim advantages over the other; both represent viable options for home and other local area networks (LANs).
Below we compare wired and wireless networking in five key areas:
- ease of installation
- total cost
About Wired LANs
Wired LANs use Ethernet cables and network adapters. Although two computers can be directly wired to each other using an Ethernet crossover cable, wired LANs generally also require central devices like hubs, switches, or routers to accommodate more computers.
For dial-up connections to the Internet, the computer hosting the modem must run Internet Connection Sharing or similar software to share the connection with all other computers on the LAN. Broadband routers allow easier sharing of cable modem or DSL Internet connections, plus they often include built-in firewall support.
Ethernet cables must be run from each computer to another computer or to the central device. It can be time-consuming and difficult to run cables under the floor or through walls, especially when computers sit in different rooms. Some newer homes are pre-wired with CAT5 cable, greatly simplifying the cabling process and minimizing unsightly cable runs.
The correct cabling configuration for a wired LAN varies depending on the mix of devices, the type of Internet connection, and whether internal or external modems are used. However, none of these options pose any more difficulty than, for example, wiring a home theater system.
After hardware installation, the remaining steps in configuring either wired or wireless LANs do not differ much. Both rely on standard Internet Protocol and network operating system configuration options. Laptops and other portable devices often enjoy greater mobility in wireless home network installations (at least for as long as their batteries allow).
Ethernet cables, hubs and switches are very inexpensive. Some connection sharing software packages, like ICS, are free; some cost a nominal fee. Broadband routers cost more, but these are optional components of a wired LAN, and their higher cost is offset by the benefit of easier installation and built-in security features.
Ethernet cables, hubs and switches are extremely reliable, mainly because manufacturers have been continually improving Ethernet technology over several decades. Loose cables likely remain the single most common and annoying source of failure in a wired network. When installing a wired LAN or moving any of the components later, be sure to carefully check the cable connections.
Broadband routers have also suffered from some reliability problems in the past. Unlike other Ethernet gear, these products are relatively new, multi-function devices. Broadband routers have matured over the past several years and their reliability has improved greatly.
Wired LANs offer superior performance. Traditional Ethernet connections offer only 10 Mbps bandwidth, but 100 Mbps Fast Ethernet technology costs little more and is readily available. Although 100 Mbps represents a theoretical maximum performance never really achieved in practice, Fast Ethernet should be sufficient for home file sharing, gaming, and high-speed Internet access for many years into the future.
Wired LANs utilizing hubs can suffer performance slowdown if computers heavily utilize the network simultaneously. Use Ethernet switches instead of hubs to avoid this problem; a switch costs little more than a hub.
For any wired LAN connected to the Internet, firewalls are the primary security consideration. Wired Ethernet hubs and switches do not support firewalls. However, firewall software products like ZoneAlarm can be installed on the computers themselves. Broadband routers offer equivalent firewall capability built into the device, configurable through its own software.
How to Build a Wireless Home Network:
The building blocks of a wireless LAN are network adapters, access points, wireless routers, add-on wireless antennas and signal boosters. Of these, only network adapters are truly required to build a wireless home network. However, many wireless LANs also utilize some of the other equipment, as explained below.
Wireless Network Adapters
Each computer you wish to connect to a WLAN must possess a wireless network adapter. Wireless adapters are sometimes also called NICs, short for Network Interface Cards. Wireless adapters for desktop computers are often small PCI cards or sometimes card-like USB adapters. Wireless adapters for notebook computers resemble a thick credit card (see Page 1 sidebar for illustration). Nowadays, though, an increasing number of wireless adapters are not cards but rather small chips embedded inside notebook or handheld computers.
Wireless network adapters contain a radio transmitter and receiver (transceiver). Wireless transceivers send and receive messages, translating, formatting, and generally organizing the flow of information between the computer and the network. Determining how many wireless network adapters you need to buy is the first critical step in building your home network. Check the technical specifications of your computers if you’re unsure whether they contain built-in wireless adapter chips.
Wireless Access Points
A wireless access point serves as the central WLAN communication station. In fact, they are sometimes called “base stations.” Access points are thin, lightweight boxes with a series of LED lights on the face (see Page 1 sidebar for illustration).
Access points join a wireless LAN to a pre-existing wired Ethernet network. Home networkers typically install an access point when they already own a broadband router and want to add wireless computers to their current setup. You must use either an access point or a wireless router (described below) to implement “hybrid” wired/wireless home networking. Otherwise, you probably don’t need an access point.
Many access point products are available on the market; see the following supplementary article for some good examples:
A wireless router is a wireless access point with several other useful functions added. Like wired broadband routers, wireless routers also support Internet connection sharing and include firewall technology for improved network security. Wireless routers closely resemble access points (see Page 1 sidebar for illustration).
A key benefit of both wireless routers and access points is scalability. Their strong built-in transceivers are designed to spread a wireless signal throughout the home. A home WLAN with a router or access point can better reach corner rooms and backyards, for example, than one without. Likewise, home wireless networks with a router or access point support many more computers than those without one. As we’ll explain in more detail later, if your wireless LAN design includes a router or access point, you must run all network adapters in so-called infrastructure mode; otherwise they must run in ad-hoc mode.
Wireless routers are a good choice for those building their first home network. See the following article for good examples of wireless router products for home networks:
Wireless network adapters, access points, and routers all utilize an antenna to assist in receiving signals on the WLAN. Some wireless antennas, like those on adapters, are internal to the unit. Other antennas, like those on many access points, are externally visible. The normal antennas shipped with wireless products provide sufficient reception in most cases, but you can also usually install an optional, add-on antenna to improve reception. You generally won’t know whether you’ll need this piece of equipment until after you finish your basic network setup.
Wireless Signal Boosters
Some manufacturers of wireless access points and routers also sell a small piece of equipment called a signal booster. Installed together with a wireless access point or router, a signal booster serves to increase the strength of the base station transmitter. It’s possible to use signal boosters and add-on antennas together, to improve both wireless network transmission and reception simultaneously.
Both antennas and signal boosters can be a useful addition to some home networks after the basics are in place. They can bring out-of-range computers back into range of the WLAN, and they can also improve network performance in some cases.
Next – WLAN Configurations
Now that you have a good understanding of the pieces of a wireless LAN, we’re ready to set them up according to your needs. Don’t worry if you haven’t settled on a configuration yet; we will cover all of them.
To maximize benefit from the directions below, have your answers ready for the following questions:
- do you want to extend your wired home network with a WLAN, or are you building a completely new network?
- how many wireless computers do you plan to network, and where in the home will be they be located?
- what operating systems do/will you run on your networked computers?
- do you need to share your Internet connection among the wireless computers? how else will you use this WLAN? file sharing? network gaming?
Installing a Wireless Router
One wireless router supports one WLAN. Use a wireless router on your network if:
- you are building your first home network, or
- you want to re-build your home network to be all-wireless, or
- you want to keep your WLAN installation as simple as possible
Try to install your wireless router in a central location within the home. The way Wi-Fi networking works, computers closer to the router (generally in the same room or in “line of sight”) realize better network speed than computers further away.
Connect the wireless router to a power outlet and optionally to a source of Internet connectivity. All wireless routers support broadband modems, and some support phone line connections to dial-up Internet service. If you need dial-up support, be sure to purchase a router having an RS-232 serial port. Finally, because wireless routers contain a built-in access point, you’re also free to connect a wired router, switch, or hub. (See diagram Page 2 sidebar.)
Next, choose your network name. In Wi-Fi networking, the network name is often called the SSID. Your router and all computers on the WLAN must share the same SSID. Although your router shipped with a default name set by the manufacturer, it’s best to change it for security reasons. Consult product documentation to find the network name for your particular wireless router, and follow this general advice for setting your SSID.
Last, follow the router documentation to enable WEP security, turn on firewall features, and set any other recommended parameters.
Installing a Wireless Access Point
One wireless access point supports one WLAN. Use a wireless access point on your home network if:
- you don’t need the extra features a wireless router provides AND
- you are extending an existing wired Ethernet home network, or
- you have (or plan to have) four or more wireless computers scattered throughout the home
Install your access point in a central location, if possible. Connect power and a dial-up Internet connection, if desired. Also cable the access point to your LAN router, switch or hub. See the diagram in the Page 3 sidebar for details.
You won’t have a firewall to configure, of course, but you still must set a network name and enable WEP on your access point at this stage.
Configuring the Wireless Adapters
Configure your adapters after setting up the wireless router or access point (if you have one). Insert the adapters into your computers as explained in your product documentation. Wi-Fi adapters require TCP/IP be installed on the host computer.
Manufacturers each provide configuration utilities for their adapters. On the Windows operating system, for example, adapters generally have their own graphic user interface (GUI) accessible from the Start Menu or taskbar after the hardware is installed. Here’s where you set the network name (SSID) and turn on WEP. You can also set a few other parameters as described in the next section. Remember, all of your wireless adapters must use the same parameter settings for your WLAN to function properly.
Configuring an Ad-Hoc Home WLAN
Every Wi-Fi adapter requires you to choose between infrastructure mode (called “access point” mode in some configuration tools) and ad-hoc (“peer to peer”) mode. When using a wireless access point or router, set every wireless adapter for infrastructure mode. In this mode, wireless adapters automatically detect and set their WLAN channel number to match the access point (router).
Alternatively, set all wireless adapters to use ad hoc mode. When you enable this mode, you’ll see a separate setting for channel number. All adapters on your ad hoc wireless LAN need matching channel numbers.
Ad-hoc home WLAN configurations work fine in homes with only a few computers situated fairly close to each other. You can also use this configuration as a fallback option if your access point or router breaks:
See also : Ad Hoc Wi-Fi Home Network Diagram
Configuring Software Internet Connection Sharing
As shown in the diagram, you can share an Internet connection across an ad hoc wireless network. To do this, designate one of your computers as the host (effectively a substitute for a router). That computer will keep the modem connection and must obviously be powered on whenever the network is in use. Microsoft Windows offers a feature called Internet Connection Sharing (ICS) that works with ad hoc WLANs.
Wireless Routers / Access Point Interference within the Home:
When installing an 802.11b or 802.11g access point or router, beware of signal in