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A recent white paper from Cisco predicts that the mobile data traffic will almost double every year to increase from 0.2 EB per month in 2010 to 3.6 EB per month 2014 . 802.11ad is one of the latest technologies in 802.11 families. According to IEEE 802.11 official Timeline, 802.11ad is still under process to be standardized and be recognized. It is expected to complete the process by Dec 2012 or earlier than that .
This is a huge evolution in telecommunication technology since 802.11ad is able to provide a very high throughput in 60GHz. This technology is further developed by Alliance of Wi-Fi and WiGig (Wireless Gigabit). For common purpose, they share a lot of intellects. Cooperation of these two companies would make high definition multimedia streaming technology emerged in the world. They announced a partnership to invent tri-band wireless solution that can operate at 2.4GHz, 5.0GHz and 60GHz frequency bands. 60GHz can provide solutions for various applications from local file transfer to high definition video transfer. Version 1.0 of specification was the achievement of alliance of WiGig that operated under 802.11ad .
802.11ad has wavelength in millimeter range which can have maximum up to 7 Giga bit per sec (Gbps) short range data transmission and possess multiple channel configurations that allowed to operate in the same space . It is 10 times faster than the highest 802.11n rate. This is a promising technology that will provide multi-Gbps throughput at short range .
The WiGig Version 1.0 specification was contributed to the IEEE 802.11ad standardization process, and was confirmed in May 2010 as the basis for the 802.11ad draft standard. IEEE 802.11ad is an amendment to the 802.11 standard that enables multi-gigabit wireless communications in the 60 GHz band .
Structure of 802.11ad
The WiGig specification defines Physical (PHY) and Medium Access Control (MAC) layers and is based on IEEE802.11 .
Physical Layer  (PHY)
As we know, the 2.4GHz and 5GHz bands used by Wi-Fi in family 802.11g and 802.11a respectively, and the 60GHz band used by WiGig is unlicensed and available worldwide. Different countries had different of spectrum available on air as shown as Figure below:
Figure 1: Worldwide spectrum availability band used by WiGig
Table 1: Channel Boundaries, GHz
2.4GHz has 84 of spectrum available, 5GHz has 605 of spectrum available and 60GHz has 7000 of spectrum available . Because the 60GHz has much more spectrum available, the channels are wider which can enable multi-gigabit data rates. The WiGig specification states that four channels with each 2.16GHz wide which is 50 times wider then then channels in 802.11n. That is why those wide channels enable WiGig to support the devices that requires extremely fast communication for instance uncompressed video transmission.
Medium Access Control  (MAC)
MAC enable IP networking exceed 60GHz. It is simplified and cheaper to produce devises that can communicate between WiGig and existing Wi-Fi using tri-band frequency which is 2.4GHz, 5GHz and 60GHz. The main key is switch transparently and imperceptibly to the users among different frequencies.
Figure 2: WiGig architecture enables tri-band
Protocol Adaptation Layers (PALs)
Protocol Adaptation Layers (PALs) in 802.11ad allow wireless implementations of specific data and display standards over 60GHz and can run those standards directly on the WiGig MAC and PHY. On the other word, PALs allow consumer to interfaces electronics (hardware) over 60GHz WiGig networks. PALs can highly improve the wireless connections because PALs are directly related to WiGig MAC and PHY rather than layered on the other protocols. That is why it can maximize the performance and reduce the power consumption.
Figure 3: WiGig Protocol Adaptation Layers (PALs)
Basically, PALs defined into two categories which is Audio Visual (A/V) and Input Output (I/O):
A/V PALs enable wireless transmission of audio visual data. These PALs enable wireless implementations of High-Definition Multimedia Interface (HDMI) and DIsplayPort interfaces and also High bandwidth Digital Content Protection (HDCP) to protect digital content transmitted between those interfaces .
I/O PALs is using computer interfaces such as USB or PCIe for high performance wireless implementations. PCIe is basically used for computer to connect the CPU and memory to I/O controller in storage application, network cards and other interfaces. I/O PALs able to improve the picture quality by connecting PCIe or USB to media and visual processors. As the result, multi-gigabit wireless synchronization can be achieved although connecting with other high speed peripherals devices .
Specification Overview of 802.11ad
Maximize performance, minimize implementation complexity and cost, enable compatibility with existing Wi-Fi and provide advanced security.
Support data transmission rate up to 7Gbps and all devices based on WiGig specification will support the gigabit data transfer rates.
Able to support from low power handheld devices for instances cell phones as well as to high performance devices such as computer. Advanced power management must be included.
Enable devices to switch transparently and imperceptibly to the users between 802.11 networks operating in any three frequency band: 2.4GHz, 5GHz, and 60GHz.
Enable robust communication at distances surpass 10 meters.
Adoption of Galois/ Counter Mode (CGM) of AES (Advanced Encryption Standard) encryption algorithm in advance security system.
Supplements and extends the 802.11 Medium Access Control (MAC) layer and is backward compatible with the IEEE 802.11 standard
Critical Challenges during design 802.11ad
The first challenge is directional nature of 60GHz signal transmission. Due to physic theory, 60GHz signal are highly directional in nature, only been transmitter and receiver are particular focused direction to get the signal from point A to point B. Any object that occurs between the paths AB which is called line of sight will block the signal immediately. Therefore, Adaptive Beam Forming Algorithms are developed to solve this difficulty due to seamless and highly robust of the signal. As shown as Figure 4, if someone walks between the transmitted signals, the devices can quickly establish a new communication path by reflecting wall, ceiling or any object in the room.
Figure 4: With highly directional transmission, beamforming can bounce the signals off walls and other objects in order to reach their destination
The second challenge is high cost of 60GHz electronic. Previously, the costing material would necessary to be sued in the circuit in order to function at 60GHz. Standard low cost CMOS manufacturing techniques had been invented to overcome this problem. This design is based on standard CMOS processor conventionally used for other types of chip such as microprocessor and consumer electronic component. This is a production of reliable design, high performance and low cost wireless solution.
The third challenge is large form factor of 60GHz antennas and packaging. Previously, most of the 60GHz system requires bulky packaging to handle the high frequency signal. Now, Micro Array Antenna Technology had been developed to overcome packaging issue. This is a technic to integrate many antennas into small are using standard low cost effective packaging processor.
Those three critical challenges are solved by SiBEAMââ‚¬â„¢s Omnilink technology , , .
application of 802.11AD
Basically, 802.11ad have 4 major applications which are:
Instant Wireless Synchronization
For example, peer to peer communication or Kiosk synchronization and data exchange.
Provide a wireless technology for gaming, backup, HD connections between A/V equipment and also with other high speed applications. It is the HD strams over HDMI or DisplayPort using A/V PAL.
A technique that used to combine wireless display using A/V PALs, synchronization and I/O using I/O PALs.
It can use native Wi-Fi and 802.11ad to support this application.
Recently, gaming engineer had invented the method with combination of 802.11ac and 802.11ad, coupled with USB 3.0, which can allow player to position the clusters of computer and entertainment hardware. USB 3.0 and gigabit Ethernet is used to connect the devices that located on a table or inside a cabinet where 802.11ac is used to link clusters across a home and 802.11ad performs as carry data to mobile devices, displays, and other gear within a room , .
Modulation and coding scheme
Modulation is a process of transforming data into analog signal. By varying one or more of the signalââ‚¬â„¢s basic characteristic such as frequency, amplitude or phase, the wirelessly transmitted signal can be modulated. During choosing the method of modulation, sectors that need to consider is cost, scalability, and reliability of wireless transmissions. There are two types of modulation and coding schemes can be used in 802.11ad which is ;
Orthogonal Frequency Division Multiplexing (OFDM)
A modulation technique that used to transmit large amounts of digital data over a radio wave. The digital signal is split into several narrow channels at different frequencies. In fact, this modulation method is first conceived in 1960s and 1970s during the experiment to minimize the interference among channels near to each other frequency band. ODFM able to support communication over longer distances with greater delay spreads. It can handle the obstacles and reflected signal in much more flexibility in order to provide the communication path. OFDM allows the maximum transmission speed up to 7Gbps. 
This modulation is leads to a single carrier transmit signal in contrast to OFDM which is a multi-carrier transmission scheme. Basically, SC results in low power consumption. That is why it is often used in small, low power handheld devices. SC allows the maximum transmission up to 4.6GHz , .
In fact, these two types of modulation pattern are sharing the common element such as preamble and channel coding. Therefore, complexity for manufacturing the devices can be reduced.
Benefit of 802.11ad
There are several advantages that need to be addressed.
Wide bandwidth and high flexibility for transmit power
These two advantages have brought benefit of multi-gigabit wireless transmission rate. According the Shannon capacity theorem, the maximum possible data rate is given by;
Shannon Capacity=Channel Bandwidth*log (Power/Noise).
From this equation, the maximum possible data rate increase with increasing of the channel bandwidth and effective transmit power .
As stated in section II-A, majority of the globe has allocated 7GHz of unlicensed spectrum which is varying between 67GHz to 66GHz. Within these frequencies band, the countries have 5GHz of continuous spectrum in common. So, devices that operate under these frequencies will not encounter regulatory problems. On the other words, customers do not have to buy a license from Federal Communications Commission (FCC) before operating equipment in these spectrums .
Narrow beam width and oxygen absorption for noise immunity and advance secure operation
Due to physic theory, oxygen attenuates 60GHz signal over long distances. On the other words, oxygen absorbs radio emissions. This is unique properties to 60GHz spectrum. The absorption process weakens the traveled signal over distance. That is why 108.11ad cannot travel far distance. While this limited distances that they can cover, it also provide interference and advantages of security if compared to other wireless technologies .
Basically, there is hard for a standard that still under development to have any disadvantages. But for sure, this technology will bring human to new era. 802.11ad is an excellent achievement in wireless technology especially its large bandwidth and high allowable transmit power.