"Category 8"
The world has recently seen the first international proposals for standardisation of "Cat. 8 / Class G" cabling aimed for data and multimedia applications in smaller installations as residential areas, but also usable in normal size installations where better than Cat. 7 / Class F performance is wanted.

Note: For simplification both cabling and components of any Class / Category will be identified only by the name "Cat." in the following parts of the present 3P Newsletter, but knowing that the correct name for a cabling rating in ISO/IEC and CENELEC is not "Category" but "Class".

The background, status, overall technical requirements and potentials of "Cat. 8" cabling are discussed in the present 3P Newsletter.

Background
The intensive work in ISO/IEC, CENELEC and TIA/EIA to prepare the Cat.5:2002 (Cat. 5e), Cat. 6 and Cat. 7 specifications is in its final stage or even completed. The efforts of standardisation of cabling will therefore be allocated to new challenges, and one evident and sadly missed area is standardisation of cabling for the private sector, the so called SOHO installations (Small Office Home Office). SOHO will likely call for new requirements due to support to multimedia applications and data.

Cabling for SOHO
New and more strict performance requirements are needed, but the installation length may on the other hand be reduced due to the smaller size of the residential areas compared with large office buildings. Typically a total channel lengh of 50 metres will be acceptable for SOHO cabling, and this is also the maximum length specified in the two presently released "Cat. 8" cable and cabling proposals.

As cabling type for SOHO an evident choise would be to use 4 pair balanced copper cabling. This would make it possible to combine data and multimedia through the same one outlet offering a high extent of simplification of cabling for the private sector. However, performance requirements to such cabling would be tough, with significantly more strict performance requirements than for Cat. 7 and to a higher bandwidth of for instance 1,2 GHz as specified by the two standard proposals.

An example of the more strict performance requirements is NEXT. When a PC and a television share the same outlet (link) a very weak incoming TV signal must be efficiently protected from the NEXT (noise) from the outgoing strong PC transmission. Consequently a minimum NEXT value of 90 dB is probably required for cables at medium and low frequencies where a Cat. 7 cabling has only a minimum requirement of 80 dB NEXT.

Improved Cat. 7 or "Cat. 8" ?
The new cabling could in principle be made in two different ways, i.e. as an enhancement of Cat. 7 limits and to also cover the extended bandwidth of 1,2 GHz, or as completely new "Cat. 8" requirements.

The improvement of Cat. 7 could appear attractive by a first look, but has two significant drawbacks. First it would delay the publication of the 2nd edition of ISO/IEC 11801 and CENELEC EN 50173 standards by years, and second it would degrade a large number of totally fine Cat. 7 components as they would not pass the new "Cat. 8" requirements.

The author therefore believes that preparation of a new "Cat. 8" specification is the natural development of cabling, for instance as an amendment to the coming ISO/IEC 11801 and CENELEC EN 50173 cabling standards.

"Cat. 8" Proposals
Two "Cat. 8" standard proposals have so far been made, i.e. a 1,2 GHz / 50 metres cable standard in CENELEC (proposed by France) and a 1,2 GHz / 50 metres cabling standard specifying both cables and connecting hardware in ISO/IEC (proposed by 3P).

The cable requirements of the two proposals are not completely identical as some parameters are more strict in the ISO/IEC proposal.

None of the proposals have been agreed by the relevant standardisation committees although they have been well received. Application committees will for instance be consulted about their interest in and need for "Cat. 8"cabling before such cabling is developed.

Name
The name "Cat. 8" appears logical to 3P as it will be easily understood without saying that the performance will be better or equal to the one of Cat. 7 for all parameters. However, the name "Cat. 8" has formally not been agreed by neither ISO/IEC nor CENELEC. The CENELEC cable standards never use the word "Category" but identify cable performance by the bandwidth, for instance 250 MHz cable instead of Cat. 6 cable. This is therefore also done for the 1,2 GHz cable proposal. The ISO/IEC committee has decided to use the name "Broadband Premises Cabling" until a name for the new "Cat. 8" cabling has been decided and standardisation work has been initiated.

Backwards Compatibility of "Cat. 8"
Backwards compatibility of "Cat. 8" cabling with Cat. 7 (and of course with Cat. 6 and Cat. 5) is vital as this will secure that low and medium data rate applications like 10 Base-T and 100 Base-T can run on "Cat. 8" installations. This means, of course, that "Cat. 8" cabling will be able to substitute Cat. 7 cabling for all applications. "Cat. 8" cables would probably be more expensive than Cat. 7 ones due to a little thicker copper conductors and more strict requirements. However, it is basically the same technology that needs to be applied for both "Cat. 8" and Cat. 7.

Applications should already exist for "Cat. 8". Drawing the parallel to the past situation of Cat. 4 and Cat.5 it appears that there are therefore significant similarities with the present situation indicating that there should be a bright future for "Cat. 8". However, Cat. 7 will of course be the only choice for the highest performance cabling until "Cat. 8" cables and connecting hardware have been standardised and are available on the market.

"Cat. 8" Requirements
The proposed "Cat. 8" requirements are available from 3P upon request.

3P has now initiated a "Cat. 8" qualification programme covering the 1,2 GHz cables and connecting hardware tested according to the requirements of both the ISO/IEC and CENELEC proposals.