Ru Bee - RuBee Disadvantages and Advantages

RuBee Disadvantages and Advantages

The major disadvantage RuBee has over other protocols is speed and packet size. The RuBee protocol is limited to 1,200 baud in existing applications. The IEEE 1902.1 specifies 1,200 baud. The protocol could go to 9,600 baud with some loss of range. However, most visibility applications work well at 1,200 baud. Packet size is limited tens to hundreds of bytes. RuBee's design forgoes high bandwidth, high speed communication because most visibility applications do not require them.

The use of LW magnetic energy brings about a number of advantages:

• Long battery life – Because of the use of low frequencies and data rates the chips and detectors can run at low speed. Using (lowest cost) 4 micrometre CMOS chip technology, this leads to extremely low power consumption. LW magnetic wave tag systems can and have achieved 15 year lives using low-cost lithium batteries. This is also the expected battery shelf life.

• Tag data travels with the asset – Because data is stored in the tag, IT (Information Technology) costs are reduced. This means that with a low-cost handheld reader one can simply read a RuBee tag and learn about the asset — manufacturing data, expiry date, lot number, etc. — without having to go to an IT system to look it up. In addition, the distance between the reader and the asset is not critical. RuBee can also write to a tag at the same range as it can read it. RFID, on the other hand, uses EEPROM memory, and writing to the tag is awkward. (In the case of RFID, range is limited, more power is required and write times are long.)

• Human Safe – A RuBee base station produces only nanowatts of radio energy. RuBee's LW magnetic waves are not absorbed by biological tissues and are not even regulated by OSHA. In fact, RuBee produces less power and lower field strengths than the metal detectors in airports and the anti-theft detectors in retail stores operating at similar frequencies — by a factor of about 10 to 100. Recently published studies show that RuBee has no effect on pacemakers or other implantable devices (Hayes et al., 2007).

• Intrinsically Safe – A RuBee base station and tag produces a low level of magnetic energy simply not capable of heating explosives or creating a spark. In independent studies carried out by the Department of Energy RuBee was given a Safe Separation Distance (SSD) of zero, and is the only wireless technology to have that rating. That means tags and base stations can be placed directly on high explosives with no risk of accidental ignition or any heating.

• High security and privacy RuBee tags have many unique advantages in high security applications. The Eavesdropping range (the range at which a person with unlimited funds can listen to tag conversations) is the same as tag range. That means if someone is listening, they must be close enough for you to be able to see them. This is not true for RFID or 802 protocols (see Wall Street Journal May 4, 2007 Credit Card Data). That means no one can secretly listen to tag/base station conversations. In addition, since RuBee tags have a battery, a crystal and sRAM memory, they can use strong encryption with nearly uncrackable one time keys, or totally uncrackable one time pads. RuBee is in use today in many high security applications for these reasons. RuBee is the only wireless technology approved for use in secure US government sites.

• Controlled volumetric range – RuBee has a maximum volumetric range of approximately 10,000 square feet (900 m²), using volumetric loop antennas — From even a small volumetric antenna of 1 sq ft (900 cm²), RuBee can read a tag within an egg-shaped (ellipsoid) volume of about 10 x 10 x 15 ft (3 x 3 x 5 m). A special feature of IEEE P1902.1 known as Clip makes it possible to place many adjacent loop antennas in an antenna farm, and read from tens to hundreds of base-stations simultaneously.

• Cost effective - With RuBee, relatively simple base stations and routers can be employed, which means receivers and card readers can be reasonably priced as compared to higher frequency transceivers. In addition, the tags often include a single chip, a battery, a crystal and an antenna, and can be priced competitively with respect to active RFID tags (those including a battery).

• Less noise – Because ambient noise in a region falls off as 1/r³, RuBee exhibits reduced susceptibility to extraneous noise. The major limit to antenna size is deep space noise.