One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.

Universal mobile telecommunications system (Universal Mobile Telecommunications System or UMTS) is one of the technologies used by mobile third-generation successor to GSM, because the GSM technology itself could not follow an evolutionary path to get to providing services considered third generation. Although initially is designed for use in mobile phones, the UMTS network is not LIMITADaa these devices and it can be used by others. What are the differences between GSM and UMTS? The GSM system operates by TDMA, ie, time is divided into slots and each user is assigned a slot, ie, a period for which data can be transmitted. Therefore each channel is shared by a number of users. The system is a UMTS (WCDMA) code division multiple access dand broadband. In this system there are no time slots and GPRS. All users transmit simultaneously on the channel, but each user signals are encoded with a unique code so that even though we think that an "indecipherable signal" is formed by using the same frequencies simultaneously, It is not, because the base station is capable of decoding and re perfectly separate each of the communicationsreceived from different users. This obviously implies a much higher channel utilization, to not share in time.

MiFi is a mobile router that acts as an access point to the Internet via 3G or later. You can connect to one or more devices at once by WiFi. It can be used with multiple WiFi devices such as desktops, laptops, tablets, smartphones, etc.

WAN, which is also known as wide area network is a network that consists of several private computers or organizations. Today with the speed that is in LANs is no longer necessary to use WAN

4G is the next generation of technology that the International Telecommunication Union has created for transferring data via the Internet. The speed is 100 MB/s downstream and 50 MB/s upstream, with a bandwidth of 20 MHz. The idea that used to wield the great value of 4G format that society is consuming more video and heavy images and this will make the mobile phone supports it. A continuación show you a small graphic comparison between 3G and 4G in the most common uses computer-related.

When we talk about RJ45 ("Registered Jack" 45) we refer to a telecommunications network interface for wired connection of voice and data equipment.

This connector has 8 pins or connections and may have a specific category depending on the data transfer speed and bandwidth (category 5e, 6, etc.)

The common application is their use in Ethernet network cables under TIA/EIA-568-B standard that defines the arrangement of pins (pinout), but can also be used for other applications.

- Direct pin diagram:

EIA-568A
Pin No.1: WHITE-GREEN
Pin No.2: GREEN
Pin No.3: WHITE-ORANGE
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: ORANGE
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

EIA-568B
Pin No.1: WHITE-ORANGE
Pin No.2: ORANGE
Pin No.3: WHITE-GREEN
Pin No.4: BLUE
Pin No.5: WHITE-BLUE
Pin No.6: GREEN
Pin No.7: WHITE-BROWN
Pin No.8: BROWN

- Schematic of crossed pins:

The crossover cable has one end with EIA-568A scheme and the other one with EIA-568B.

The Wifi technology is a wireless communication mechanism between devices. This technology allows you to connect devices such as computers, laptops, mobile etc... to the Internet or communicate with the devices themselves.

Applications can be several, among the most common are the access points, ideal for giving and sharing a connection signal to multiple devices. It is the typical configuration of a home user.
Repeater, ideal to repeat and amplify weak signal.

The power and range between devices basically depends on the antenna and its hardware.

The wireless signals work under a unified standard regulations, the standard that is based on the IEEE 802.11. These include IEEE 802.11b, IEEE 802.11g and IEEE 802.11n working at 11 Mbit/s, 54 Mbit/s and 300 Mbit/s, respectively.
Being any device with a standardized protocol such technology can connect to another using the same technology, making it a kind of universal connection.

The wireless networks are characterized by the ease and convenience of making connections in infrastructure, since it is not necessary to perform network cable installations.
it also allows connecting a lot of devices to a single node.

Depending on the quality and type, network cables are classified into categories that help us know the characteristics of them.

The categories of network cables most commonly used are:

- Category 5
- Category 5e
- Category 6
- Category 6
- Category 7

As can be seen, category 5e (enhanced or improved) and category 6A (Augmented), are an improvement of categories 5and 6, respectively, which it has improved the top speed and bandwidth.

The higher the category, the higher the speed of maximum data, the maximum 100 meters distance as its standard.

You can see a table which shows the 5 categories, where V is the maximum velocity, D is the maximum and MHz frequency which can work away.