A handover that transfers an active connection and its service context between access points, base stations or nodes that use the same radio access technology or access type (for example cell‑to‑cell in the same LTE network or AP‑to‑AP within the same Wi‑Fi subnet).

Principle

Horizontal handover relies on intra‑technology measurement, resource reservation and context transfer mechanisms that assume compatible addressing, authentication and QoS semantics, enabling lower‑overhead continuity within a homogeneous access domain.

Demonstration

Illustrative scenario → A user moves from one LTE cell to an adjacent LTE cell; measurement reports and handover algorithms select the target, context is transferred and the bearer is switched; consequence → the ongoing voice call continues with only a brief interruption and modest signalling overhead because addressing and authentication remain within the same RAT and operator domain.

Misapplication

Assuming horizontal handover always stays within a single administrative domain: one may plausibly believe same‑RAT implies single operator; the semantic error is conflating radio‑technology homogeneity with administrative ownership—horizontal handover between domains requires inter‑domain agreements and may be treated as roaming.

Consequence

Horizontal handovers enable efficient mobility with relatively low signaling and delay compared with cross‑technology transfers, but still consume radio and control plane resources, can fail if measurements are stale, and may require rapid reallocation of QoS parameters.

Reversal

Where cells belong to different administrative domains or use different operator policies, a same‑technology transfer may be constrained by roaming, interconnect policies or lack of shared context; conversely, advanced make‑before‑break designs can render horizontal handover effectively seamless within a domain.

Boundary

Clearly within → Transfer of an active bearer between cells of the same LTE network with local context transfer. Boundary case → Handover between two Wi‑Fi APs operated by different providers but on the same channel and SSID—technically same RAT but administrative factors affect outcome. Clearly outside → Handover between heterogeneous access technologies (this is vertical handover).

Semantic Tension

Low‑Latency Continuity ↔ Control‑Plane Load — achieving minimal interruption demands quick decisions and signaling that increase control‑plane load; conserving control‑plane resources increases interruption risk.

Synthesis

Horizontal handover is the primary mechanism for low‑friction mobility inside a homogeneous access domain; its relative simplicity compared with vertical handover depends on shared addressing, authentication and QoS models, not on absence of administrative or policy complexity.