Daily Archives: July 21, 2015

How do Airplanes Offer Onboard Wi-Fi?

Not long ago, air travel meant you had to switch off your phone and other electronic devices carried. Even for long-distance air travel, people had to put up with in-flight magazines and movies for entertainment. Fortunately, changes have been made – with more to come.

Today, people value connectivity more than ever. Passengers admiring aerial views prefer tweeting about their experiences and follow up with pictures – not content with merely complaining about the food to their neighbors. Airlines are responding to such demands and nearly 40% of the US fights now provide in-flight Wi-Fi, as do several international long-haul flights.

Onboard Wi-Fi technology is still in the nascent stages and significant problems abound. Fliers are not happy with the slow speeds and unreliable connection, especially when the cost for each device for a full flight is high. A FlightView survey of 600 US passengers inferred Wi-Fi offered in-flight satisfied only about 28% of business travelers. The key problem lies in the manner an airplane’s onboard Wi-Fi technology works – there are two main routes.

A US provider, GoGo, has a network system of 3G ground stations all across the US. Planes communicate with these stations when flying overhead. Although the system is simple, bandwidth can be as low as 3Mbps for the entire flight, making it inadequate per customer for streaming videos.

The company is now moving over to ATG-4 technology, with planes requiring dual modems and directional antennas. That boosts the total bandwidth to about 9.8Mbps – still not a significant increase. Planes flying over the seas cannot link to ground stations, which further worsens the connectivity.

As an alternative approach, some airlines allow planes to connect via a satellite. Earlier, they used legacy L-band technology, which was slow and rather expensive. Now using the higher-frequency Ku-band satellites is more common as they work at 12-18GHz. Not only does this offer good performance, it is economical as well. For example, the FlyNet system from Lufthansa claims its download speed to the aircraft reaches 50Mbps, even at the middle of the ocean.

Passengers can optionally connect in two ways. For example, OnAir, a telecom company, allows connections via GSM and Wi-Fi. If you are using a mobile phone, turn on your GSM mobile phone network and use it just as you would on international roaming. Your regular phone bill reflects the costs.

Wi-Fi connection within the aircraft depends on the airline’s own rules. You pay for bandwidth, time of use or distance traveled. Most service providers offset operational expenses and cost of technology (bandwidth) against the number of passengers opting for the service. That decides the rate the airline charges its passengers for the service.

Airlines are discovering the future for on-board connectivity lies in moving towards the Ka-band, which works at 26.5-40GHz via satellites – potentially increasing the capacity nearly 100 times that offered by the present Ku-band. According to ViaSat, a satellite company, this can mean offering each passenger a speed of about 12Mbps, while lessening the cost about five times – a significant progress for frequent, long-distance fliers.

How Does A Measurement Pillow Work?

In human life, sleep is the period when the body rejuvenates. Two body systems regulate the timing and amount of sleep – the sleep/wake homeostasis and the circadian biological clock. Depending on external circumstances and the health of the individual, people experience different levels of alertness and sleepiness throughout the day. After being awake for a long time, the sleep/wake homeostasis tells the body it is accumulating the need for sleep and that causes us to feel sleepy. It also regulates the period of sleep throughout the night, to let us make up for the hours we will remain awake. The sleep/wake homeostasis balances the wakefulness and sleep periods in the body.

We also have an internal circadian biological clock that regulates the timing of wakefulness and sleepiness throughout the day. The circadian rhythm rises and dips at different times of the day. Typically, an adult has the strongest sleep drive between 2:00-4:00 am and again in the afternoon between 1:00-3:00 pm. However, this varies from person to person.

Sometimes, due to various reasons, things go wrong with the body systems regulating the timing and amount of sleep. Doctors advise monitoring your sleep to know where things are going wrong. However, this becomes a “Catch 22” situation – if you sleep, it is impossible to monitor how you sleep and you cannot sleep if you are monitoring. Now, there is a solution to this dilemma – a measurement pillow.

A chiropractor, Rick Loos, founder of the company Proper Pillow, is all set to develop a pillow containing a set of sensors to monitor the quality of your sleep. The pillow will monitor your sleep position throughout your sleeping time, collect the data and transmit them to an app on your smartphone.

Proper Pillow Plus will have a network of pressure sensors to collect the data. It will use BLE or Bluetooth Low Energy to transmit this data. Of course, this requires a power source, a sensor network with ADCs, and a micro-controller with a BLE radio. Normally, all data collected will remain stored until you decide to transmit it to your smartphone. Watch the pillow doing its work here. Proper Pillow also provides better sleep by giving its user a proper spine alignment.

According to Dr. Loos, the Proper Pillow Plus will contain 9-12 pressure sensors, a digitizer board, a micro-controller with Bluetooth capabilities, a battery, a microphone and a temperature probe. It will use 3-point redundancy to detect correctly the head and neck of the sleeper. The microphone will record various sounds such as the person’s breathing and external sounds such as a dog’s bark. The pillow will also record the ambient temperature to know if the sleeper woke up due to changes in temperature. The pressure sensors will determine how much time the user spent on his back or on his side.

Usually, the hardware will remain in low-power mode to maximize power efficiency. The algorithm wakes the hardware only when there is a change is pressure due to the sleeper’s movements. The slow changes in pressure and temperature permit low-speed digitization.

What are Counterfeit SD Cards?

Many of us use SD or Secure Digital memory cards, but seldom do we check if the total capacity actually matches that specified on the card. According to the Counterfeit Report, several dishonest sellers on Alibaba, Amazon, eBay and other reputed sites offer deep discounts for high capacity cards. They use common serial numbers with cards and packaging nearly identical to the authentic products from all major SD card brands.

According to tests conducted by the Counterfeit Report, although the cards work, buyers usually purchase a card based on the specifications printed on it. What they think and buy as a 32GB SD card, may turn out to be a counterfeit with a capacity of only 7GB. Counterfeiters usually overwrite the real memory capacity, imprinting a false capacity figure to match any model and capacity they prefer. Usually, the actual memory capacity cannot be determined by simply plugging the card into a computer, phone or camera. Only when the phony card reaches its limit, it starts to overwrite files, leading to lost data.

According the Craig Crosby, publisher of the Counterfeit Report, such fake cards also come in capacities that do not exist in any product line and counterfeiters target mostly cards above 32GB. They make a great profit on selling fake cards, with practically no consequence.

Usually, people cannot make out counterfeit cards from real ones, until these stop working. Usually, the blame falls on the manufacturer for making faulty products. This may happen even if you buy from a major retailer, as counterfeiters buy genuine items, only to exchange them unopened with their fakes.

Although software packages are available to test whether the card capacity matches the specifications on its packaging, organizations find it time-consuming, especially if they have bought cards in bulk. Additionally, the problem is not with SD cards alone, counterfeiters make fake portable flash drives including USB sticks as well.

Although the SD Association does make standards and specifications for SD cards to promote their adoption, advancement and use, they do not monitor the trade of products such as SD memory cards. The responsibility of counterfeit SD cards falls in the realm of law enforcement.

Manufacturers of SD memory card products can contract with several SD standards-related organizations for different intellectual property related to SD standards. Additionally, SDA member companies can resort to compliance and testing tools for confirming their products meet the standards and specifications, providing assurance to users about interoperability with other products of similar nature.

Consumers, especially bulk purchasers, should be careful to buy from authorized resellers, distributers and sellers. The best resource for any enquiry is the manufacturer of the SD memory card product.

This malaise is not restricted to counterfeit SD cards alone. It is a part of a larger problem. According to the Counterfeit Report, several other items face the same situation. Phony items exist for iPhones, other smartphones, airbags and many other peripherals such as chargers. It is very difficult for consumers to make out the counterfeits and many are even unaware of the existence of such phony high-end items.