NEWS & ARTICLES

DataMax® 10Gig Shielded or Unshielded Cable Minimizes Alien Crosstalk Noise

July 2006

The IEEE 802.3 Ethernet committee has identified Alien Crosstalk (AXT) as the critical noise parameter that must be controlled to successfully implement 10 Gigabit Ethernet on copper balanced pair cabling systems. Quabbin Wire & Cable's next-generation patch cable, DataMax 10Gig, helps solve this problem.

DataMax 10Gig patch cable has excellent resistance to Power Sum Alien Crosstalk (PSAXT) noise with more than 10 dB margin over the TIA/EIA-568-B.2-10 proposed minimums. Testing DataMax 10Gig cable using TIA's proposed 6 cables around 1 configuration, produces measured values so low they are very close to the noise-floor of the network analyzer. This assures reliable 10GBase-T Ethernet transmission for Category 6 channels.

This LSZH jacketing compound also has superior electrical characteristics as compared with conventional PVC jackets. Therefore, LAN cables jacketed with this new material have improved data transmission characteristics and lower attenuation, combined with the flame/smoke/corrosive gas properties detailed above. Category 5e and 6a unshielded (UTP) designs are tested to 350 MHz and 500 MHz respectively.

Quabbin Wire & Cable Co., Inc. produces thermoplastic shielded and unshielded cables for electronic applications and high-speed data transmission.

PSAXT is the total interference transmitted from the pairs in adjacent cables into the pairs of the victim cable. Since this noise is not a signal generated by the victim, transceiver cancellation circuitry cannot be “trained” to cancel it out from the intended data stream. Because 10GBase-T Ethernet protocol is signaling at high data rates and low signal levels, it is particularly susceptible to very low noise levels. Alien Crosstalk noise levels are inherently low and subject to attenuation as they propagate toward the10GBase-T transceivers at the channel ends. Thus, PSAXT is predominantly a channel end-effect.  

Since patch cords are usually installed at both ends of a channel, successful transmission of 10 Gigabit Ethernet most often depends on patch cable PSAXT performance. Cords made with DataMax 10Gig cable provide the needed performance headroom for Category 6a channels.  

These patch cables have an impedance of 100 Ohms, are shielded or unshielded, have a dual-layer jacket, and are RoHS compliant. The designs are relatively small, do not use an internal spline, or have over-sized copper conductors. Therefore, these stranded cables are easily terminated using high-performance modular plugs with standard dimensions.  

To terminate the unshielded cable, an appropriate length of outer jacket is cut away, which also removes the AXT suppression layer between the jackets. The inner jacket and insulated conductors are then prepared and terminated as required by the specific plug being used. The outer jacket is usually covered by a strain-relief boot or shrink-tube. Terminating the shielded design is similar except the shielding tape is appropriately terminated by the specific plug design.  

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