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 區域, 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
四個問題. 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)
模型號碼 和 強度成員材料 (never trust the model alone)
纖維計數 (1 / 2 / 4 / 習俗)
Fiber grade — insist onG .657. A2for any FTTH deployment that may be upgraded to XGS-PON
護套材料 (LSZH for indoor and most modern outdoor; PE only where LSZH is not required)
喺額定靜態彎曲半徑下對樣本進行彎曲測試，然後喺 OTDR 上面重新測量損失 (一個 0.1 dB 或以上嘅跳躍需要批量審查)
應該會引發拒絕或者重新談判嘅紅旗
型號同實體構造唔啱 PO
當樣本經過熱測試嗰陣， LSZH 鞘會發出明顯嘅塑膠氣味 (表示唔合規嘅化合物)
貨件冇提供批次級別測試數據
金屬強度構件喺安裝之前會出現早期氧化
印刷標記每隔一段時間就會污糟或者缺失 — 會令客戶方面嘅驗收測試失敗
底線 — 將模型同部署配對
買條線好係一個翻譯行為. 個客話「我哋需要 FTTH 最後一英里,” 真正嘅意思係 “ 我哋需要適合呢個部署環境嘅特定模型, 緊張情況, EMI 風險, 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
兩者都唔係普遍更好 — 正確嘅選擇取決於部署. 鋼絲每美元提供更高嘅拉伸強度，而且仍然係標準室內住宅 FTTH 最經濟效益嘅選擇. 玻璃鋼 (非導電纖維增強塑膠) 係有活躍 EMI 嘅環境嘅正確選擇, 閃電風險, 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. 然而, if the cable uses a金屬強度構件, 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?
大概 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 和 200+ 米, deploy ADSS cable, which is engineered for longer aerial runs.
Can I bury GJYXCH cable directly underground?
唔係. GJYXCH is jacketed for aerial exposure to UV and weather, not for soil contact, ground moisture pressure, or rodent protection. 直接埋葬, 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 自 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 長期. 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, 剝開個鞘, 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?
