Таъминкунандаи шумо танҳо ба шумо панҷ рақами модели ноқилҳои гуногунро иқтибос овард - GJXFH, Маъшуща, Gjycchch, Gjickfch, GJFJU. Пеш аз он ки ТҶ ҳаракат кунед, шумо бояд ба як савол ҷавоб диҳед: ки ин лоиҳа воқеан ба кадоме ниёз дорад?
Ин дастур барои шахсе, ки ин қарорро қабул мекунад, навишта шудааст. Он аз навсозии "кабели нахи нахӣ чист" мегузарад (ки дар мо зиндагй мекунад Роҳнамои кабели нахи оптикӣ) ва рост ба интихоби сатҳи моделҳо мегузарад.
Агар шумо барои паҳнкунии FTTH харед, ноқилҳои таркандаро ба ISP-ҳои минтақавӣ дубора фурӯшед, ё онҳоро дар тарҳи лоиҳа муайян кунед, шумо ин корро тақрибан дар даҳ дақиқа анҷом медиҳед ва бо интихоби модели муҳофизатшаванда берун меравед.
Ҳарфҳои GJXFH воқеан чӣ маъно доранд
Рамзҳои модели кабелии чинӣ пайравӣ мекунанд YD / T 1258 стандарти телекоммуникатсионӣ. Пас аз он ки шумо намунаро омӯзед, ҳар як номи модели оянда мисли варақаи мушаххас хонда мешавад:
Санҷиши воқеияти харидор: Ҳеҷ гоҳ танҳо рақами модели кабелро қабул накунед. Ҳамеша тасдиқ кунедмаводи узвҳои қувват ваjacket materialin writing on the PO or the datasheet. Two suppliers can quote you “GJXFH” and ship physically different products. The datasheet is truth. The model code is a hint.
Steel, FRP, or Aramid: Choose the Strength Member Before the Model Number
Once you know the three families of strength members, the model number almost picks itself. Here is what changes across the three materials:
Нахи оптикӣ маълумотро ҳамчун нур тавассути ядрои шиша интиқол медиҳад. Ин раванд астасосан ба дахолати электромагнитӣ эмин аст - далеле, ки шумо метавонед ба ҳар як муштарие, ки аз "сағ" дар хат аз моторҳои наздик нигарон аст, иқтибос оварда метавонед, трансформаторхо, ё лифтҳо. Нур ба EMI-и атроф парво надорад.
Аммо сими атрофи нах як ҳикояи дигар аст.
Агар сими тарканда истифода барад аузви қувваи металлӣ, ки металл гузаронанда аст. Дар зери зарбаи барқи наздик, a high-voltage induction event, or a strong transient on a paralleled AC line, the metal element inside your drop cable can pick up induced current. When both ends of that cable terminate near active electronics (an ONT in the home, a distribution panel in a splice enclosure), the induced current has a path to ground — through your equipment.
This is why installers in lightning-prone regions, along high-voltage corridors, or near substations often specifynon-metallic drop cables (FRP or KFRP variants). The optical performance does not change. The risk profile does.
Pro tip for buyers: If your customer is in Southeast Asia’s monsoon belt, along a rural high-voltage transmission corridor, in the Middle East desert with high dust-storm static, or specifying a hospital / зеристгоҳи / MRI project, ask them a single upstream question: “Is a fully non-metallic drop cable required or preferred?»That one question narrows five models down to two.
GJXFH — The Indoor Bow-Type Workhorse
GJXFH is what most residential FTTH rollouts install between the building’s distribution box and the subscriber’s ONT. It is designed for indoor conditions: temperature-stable environments, protected pathways, moderate pulling forces during initial installation.
Typical 1-fiber GJXFH datasheet (based on a real production spec):
Параметр
Арзиш
Шумораи нахҳо
1 (also 2 / 4-core versions)
Навъи нах
G.657.A2 bend-insensitive single mode
Attenuation @1310 nm
≤ 0.4 дБ/км
Attenuation @1550 nm
≤ 0.3 дБ/км
Macro-bending loss @1625 nm, 7.5 mm × 1 turn
≤ 1.0 дБ
Jacket dimensions
3.0 × 2.0 мм (ЛСЖ, сиёҳ ё сафед)
Аъзои қувват
0.5 мм (steel or FRP, confirm on PO)
Long-term tensile load
40 Н
Short-term tensile load
80 Н
Мин. радиуси хам кардан (динамикӣ / статикӣ)
30 мм / 15 мм
Ҳарорати амалиётӣ
-40 ба +70 °C
Ҳарорати нигоҳдорӣ
-40 ба +70 °C
Why G.657.A2 matters more than the price tag
Two drop cables can look identical on paper, differ by only $0.02 per meter, ва ҳоло ҳам барои ояндаи муштарии худ интихоби хеле гуногун кунед.
G.657.A1 ба каҷҳои мӯътадил кор мекунад, аммо якбора дар радиусаш ~10 мм паст мешавад.G.657.A2 - нахи дар дохили мушаххасоти дар боло зикршуда - ҳадди аксарро нигоҳ медорад 1.0 дБ талафоти макропечӣ ҳатто дар а 7.5 мм радиуси хам кардан дар 1625 нм.
Агар харидор аз шумо пурсад, ки оё версияҳои "GJXFH берунӣ" вуҷуд доранд, ҷавоби самимӣ нест. Он чизе ки ба онҳо лозим астGjycchch ёGjickfch — кабелҳои беруна бо паёмнависии ҳамгирошуда. Бихонед.
GJXH - Намуди камон дар даруни пӯлод мустаҳкам
GJXH аксар вақт бо GJXFH дар каталогҳои таъминкунандагон ба ҷои ҳамдигар истифода мешавад, ва нофаҳмиҳо воқеӣ аст. Дар мутолиаи мо дар бораи бозор, фарки амалй ин аст: GJXH пайваста бо як узви мустаҳками сими пӯлоди фосфатӣ ва рейтинги тобиши каме баландтар нисбат ба варианти нишондодашудаи FRP мефиристад.
Варақаи маълумотии маъмулии 2-нахи GJXH:
Параметр
Арзиш
Шумораи нахҳо
2 (also 1 / 4-core versions)
Навъи нах
G.657.A2 (тасдиқ A1 против A2 оид ба фармоиш)
Attenuation @1310 nm
≤ 0.4 дБ/км
Jacket dimensions
3.1 × 2.0 мм (ЛСЖ, сиёҳ)
Аъзои қувват
2 × 0.45 мм сими фосфатдор
Long-term tensile load
100 Н
Short-term tensile load
200 Н
Мин. радиуси хам кардан (динамикӣ / статикӣ)
60 мм / 30 мм
Ҳарорати амалиётӣ
-20 ба +60 °C
Хатои маъмултарин бо GJXH
Мо дидем, ки техникхо GJXH-ро ба воситаи каналхои 20-метра мекашанд, холигии шифт, ё дар масофаи кӯтоҳи ҳавоӣ. Дар ҳар яке аз ин ҳолатҳо ҷойгиркунӣ дар рӯзи аввал кор мекард ва пас аз шаш моҳ шикоятҳои муштариёнро ба вуҷуд меовард - микрошиканиҳо дар дохили нах, сустшавии тадриҷан, ва занги хидматӣ барои иваз кардани иҷро.
А 100 N long-term tensile rating means the cable can hold its own weight and moderate pulling forceonce installed and static. It does not mean you can drag it through 15 meters of conduit against friction. If your installer needs meaningful pulling force, spec a cable rated for it — usually GJYXCH at 300 N long-term, even for a short indoor-to-outdoor transition.
Real-world scenario: A buyer in East Africa reported drop cable failures after three months of service. Root cause: their installer used GJXH indoor cable for a 40-meter run through a rooftop conduit because it was on hand. Within one rainy season the LSZH jacket had absorbed enough moisture at exposed conduit joints to induce microbending. The fix was a rework with GJYXCH — and a written material spec on every future PO.
GJYXCH — Self-Supporting Outdoor Drop for Aerial FTTH
GJYXCH is the outdoor workhorse: designed for aerial deployment between utility poles, engineered to hold its own weight over spans up to ~80 meters, and jacketed to survive UV, temperature swing, and moderate rain load.
The word matters. A self-supporting drop cable carries its own dead weight plus wind and (in colder climates) ice load, without requiring a separate lashing wire. The integrated messenger inside GJYXCH is what does that work.
Барои масофаи то ~ 80 метр ин тарҳ самаранок ва арзон аст. Бештар 80 метр — гузаргоххои дарозтари рох фикр кунед, гузаргоххои дарьё, ё ҳавоии деҳот дар байни қутбҳои дуртар аз ҳам мегузаранд - геометрияи паёмбар дигар пастшавӣ ва шиддати заруриро нигоҳ намедорад. Дар он ҷо Кабели ADSS мегирад.
Two scenarios drive customers to fully non-metallic drop cables:
Scenario one — active EMI or lightning risk.Substations, high-voltage transmission corridors, telecom-power co-siting projects, ва (in some regions) coastal areas with high atmospheric static. In these environments the customer specification often mandates dielectric drop cables to eliminate any induced-current path.
Scenario two — regulatory or contract mandate.Hospitals near MRI rooms, some airport / харбй / secure-facility deployments, and specific European telco frameworks that require dielectric last-mile cabling.
For those cases:
Gjickfch— outdoor self-supporting version with FRP-based structure instead of steel messenger
GJFJU— fully non-metallic indoor bow-type with aramid (KFRP) аъзоёни қувват
Both variants are available on order rather than as standard stock. Lead times run 1–3 weeks longer than the steel-wire equivalents, and the price index sits at roughly 1.6–2.2× the corresponding metallic version. The buying decision should therefore be“is this project actually one of those two scenarios,»not“do we want non-metallic just to be safe.”Over-specification is a real cost driver.
The Drop Cable Decision Tree — 4 Questions, 1 Модели
FTTH Drop Cable Selection · 4-question decision tree
Diagram: FTTH drop cable model selection logic · Source: FIBCONET engineering team
The decision reduces to four sequential questions. Ask them in this order and the correct model falls out:
Is the deployment indoor or outdoor? Indoor → GJXFH or GJXH · Outdoor → GJYXCH or GJYXFCH
For outdoor: is the cable installed aerially between poles, with no separate messenger wire? Yes → self-supporting variant (GJYXCH or GJYXFCH) · No → armored outdoor cable such as GYTA53
Is a fully non-metallic cable required (EMI zone, lightning-prone, hospital, contract-mandated dielectric)? Yes → FRP or KFRP version (GJXFH-FRP indoor, GJYXFCH outdoor, GJFJU for special deployments) · No → steel-reinforced version is fine
Is cost-per-meter more important than a premium feature set? Yes → steel wire strength member · No → FRP or KFRP for the longer-service-life scenarios above
Four questions. Five models. One picked cable.
Before You Sign the PO: A Drop Cable Buying Checklist
Print this section, share it with your procurement or engineering team, and use it every time you request a quote or receive a shipment.
Specification checklist (put these on the PO in writing)
Рақами модел ва маводи узвҳои қувват (never trust the model alone)
Шумораи нахҳо (1 / 2 / 4 / custom)
Fiber grade — insist onG.657.A2for any FTTH deployment that may be upgraded to XGS-PON
Маводи курта (LSZH for indoor and most modern outdoor; PE only where LSZH is not required)
Jacket color (black is standard outdoor; white or grey may be requested for indoor visibility)
Reel length (typical 2–3 km per drum; confirm before large orders)
Print marking format (sequential meter marks, batch code, and any customer branding)
Certifications required for the destination country (CPR for EU building applications, ANATEL for Brazil, UL/ETL for North American indoor risers)
Quality verification checklist (do these on receipt)
Every reel should ship with a factory OTDR trace and attenuation report bearing a batch number
Visually inspect the sheath for consistency, embedded print, and any color inconsistency
Random-sample a 1-meter section: strip the sheath, confirm strength member matches PO spec
Bend-test a sample at the rated static bend radius and re-measure loss on an OTDR (а 0.1 dB or greater jump warrants a batch review)
Red flags that should trigger a rejection or renegotiation
Model number and physical construction do not match the PO
LSZH sheath emits an obvious plastic smell when a sample is heat-tested (indicates non-compliant compound)
No batch-level test data supplied with the shipment
Metal strength member shows early oxidation before installation
Print marking is smudged or missing at intervals — will fail acceptance testing on the customer side
Bottom Line — Match the Model to the Deployment
Buying a drop cable well is an act of translation. The customer says “we need FTTH last-mile,” which really means “we need the specific model that fits this deployment’s environment, tension profile, EMI risk, and lifecycle.” The decision tree above turns that translation into four questions.
The single most common mistake we see across the region is not overpaying — it is under-specifying. A GJXH indoor cable pulled through a rooftop conduit costs less on the invoice and costs more in the truck rolls it triggers. Spec the model to what the cable will actually experience over its service life, not to what feels cheapest on the day of the PO.
If you would like a printable side-by-side view covering all five models discussed above — you can download it from ourFTTH Drop Cable resource hub. We update the sheet quarterly.
Frequently Asked Questions About FTTH Drop Cable Model Selection
What is the difference between GJXFH and GJXH?
GJXFH ва GJXH ҳарду кабелҳои камонҳои дарунӣ мебошанд. Дар Чин сахт YD/T 1258 конвенсияи номгузорӣ, ҳарфи F дар GJXFH як узви қувваи FRP ғайриметаллӣ нишон медиҳад, дар ҳоле ки GJXH металлиро нишон медиҳад (одатан пулоди фосфатдор) узви қувват. Дар амал, номи завод гуногун аст - баъзе таъминкунандагон кабелеро бо нишони GJXFH бо сими пӯлод дар дохили он мефиристанд. Ҳамеша маводи узви қувватро дар фармоиши хариди худ тасдиқ кунед, на танҳо рамзи модел.
GJXFH чӣ маъно дорад?
Ҳар як ҳарф атрибути физикиро дар зери YD/T 1258 рамзгузорӣ мекунад.Г сими оптикии коммуникатсияро истифода мебарад, Ҷ онро ҳамчун кабели дарунӣ қайд мекунад, X навъи камонро муайян мекунад (шабпарак) бахшҳои Фароӣ, Ф категорияи аъзои қувваро муайян мекунад, ваХ куртаи беруниро муайян мекунад. Якҷоя хонед, GJXFH маънои як сими тарки якнахи дарунӣ бо як узви мустаҳкам ва ғилофи беруниро дорад. (маъмулан LSZH).
Can I use indoor drop cable such as GJXFH outdoors?
Не. Indoor drop cables use LSZH jackets that are not UV-stabilised for continuous sunlight exposure, and their cross-section is not designed to survive ice load, wind stress, or outdoor moisture. For aerial FTTH deployments between poles, use GJYXCH (steel messenger) or GJYXFCH (non-metallic messenger). For duct or direct-burial use, specify an armored outdoor cable such as GYTA53.
Is FRP or steel wire better for a drop cable strength member?
Neither is universally better — the correct choice depends on the deployment. Steel wire delivers higher tensile strength per dollar and remains the most cost-efficient option for standard indoor residential FTTH. FRP (non-conductive fiber-reinforced plastic) is the correct pick for environments with active EMI, lightning risk, or proximity to high-voltage lines, where a metallic path to ground inside the cable would create a hazard for the connected ONT or distribution equipment.
Are optical drop cables affected by nearby high-voltage lines or lightning?
The optical fiber inside the cable is fundamentally immune to electromagnetic interference — light does not respond to EMI. SFP-и якмоҳа аз сабаби истифодаи воҳиди нурпошии гуногун нисбат ба SFP-и бисёрмоҳа қиматтар аст, if the cable uses aузви қувваи металлӣ, that metal can pick up induced current from a nearby lightning strike or strong AC transient, and that current has a path through the cable ends to your terminating equipment. For deployments near substations, transmission corridors, or in lightning-prone regions, specify a fully non-metallic (FRP or KFRP) variant.
What is a self-supporting FTTH drop cable?
A self-supporting drop cable has an integrated messenger element — usually a steel wire in GJYXCH or an FRP rod in GJYXFCH — that carries the cable’s own weight across an aerial span between two support points, typically utility poles. This eliminates the need for a separate lashing wire, simplifying aerial installation. Typical maximum span is ~80 meters; longer runs should use ADSS cable instead.
What is the maximum aerial span for a GJYXCH drop cable?
Approximately 80 meters between support points, under standard conditions. Beyond that distance, cable sag exceeds compliance limits under wind and ice load, and the messenger tension can compromise pole hardware. For spans between 80 ва 200+ метр, deploy ADSS cable, which is engineered for longer aerial runs.
Can I bury GJYXCH cable directly underground?
Не. GJYXCH is jacketed for aerial exposure to UV and weather, not for soil contact, ground moisture pressure, or rodent protection. Барои дафни бевосита, use an armored cable such as GYTA53 with a steel-tape armor and appropriate sheathing.
How long is a standard FTTH drop cable per reel?
Standard reel length is typically 2 ба 3 kilometers for indoor GJXFH / GJXH and outdoor GJYXCH. Custom reel lengths and larger drums can be produced on order — confirm both the standard offering and any project-specific length requirement with your supplier before finalizing the PO.
What tensile strength does a drop cable actually need for my project?
It depends on the installation scenario, not on the cable name. Wall-run or short indoor deployments typically require 40–100 N long-term tension (GJXFH or GJXH). Conduit pulling, ceiling voids, and short aerial transitions require higher rated cables — even for short outdoor spans, spec GJYXCH at 300 N дарозмуддат. Under-speccing the tensile rating is the single most common cause of latent micro-fracture failures we see in the field.
How do I verify drop cable quality before accepting delivery?
Request a factory OTDR trace and attenuation report for every reel, keyed to the batch number. Visually inspect the sheath for consistent color, embedded print marking, and no material inconsistency. Random-sample a short section from each shipment, strip the sheath, and confirm that the strength member material physically matches your PO specification. Any mismatch between the PO and the actual construction should trigger an immediate quality dialogue with the supplier.
What fiber grade should I specify for future-proof FTTH deployments?
Муайян кунедG.657.A2or higher. Older-generation G.657.A1 fiber shows significant macro-bending loss at bend radii below 10 мм, especially at 1625 nm — the wavelength window used for XGS-PON 10G FTTH network expansion. Deploying A1 today may force an operator into a costly network re-cable when they upgrade. A2 fiber holds ≤ 1.0 dB loss at a 7.5 мм радиуси хам кардан дар 1625 нм, effectively covering the operator’s next upgrade cycle at a marginal cost premium.
