قارن الطرق

	الوصول المتعدد بالاستشعار الحامل مع تجنب التصادم (CSMA/CA)	بروتوكول الوصول العشوائي ALOHA المشقوق
المجال	الاتصالات	الاتصالات
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1990	1970
صاحب الطريقة	Phil Karn	Norman Abramson and Lawrence Roberts
النوع	random access protocol	random access protocol
المصدر التأسيسي	Karn, P. (1990). MACA—a new channel access method for packet radio. In Proceedings of the ARRL/CRRL Amateur Radio 9th Computer Networking Conference, 134-140.	Roberts, L. G. (1975). ALOHA packet system with and without slots and capture. ACM SIGCOMM Computer Communication Review, 5(2), 28-42.
الأسماء البديلة	medium access control, WiFi MAC	random access, medium access
ذات صلة	3	3
الملخص	CSMA/CA is a random access protocol for wireless medium access control, designed to enable multiple devices to share a wireless channel while minimizing collisions. Introduced by Phil Karn in 1990, it is the foundation of WiFi (IEEE 802.11) and is now the de facto standard for unlicensed spectrum access. CSMA/CA combines carrier sensing (listen before transmit) with collision avoidance (RTS/CTS handshake) to improve channel efficiency and fairness, avoiding the efficiency loss of pure random access (Aloha).	Slotted ALOHA is a fundamental random access protocol enabling multiple devices to share a wireless channel without centralized coordination. Introduced by Abramson (1970) and refined by Roberts (1975), it divides time into fixed slots and allows devices to transmit at the beginning of a slot with a fixed probability. While simple and elegant, Slotted ALOHA achieves only 37% channel utilization under saturation (optimal traffic load), a fundamental limit discovered by Abramson. Despite this limitation, Slotted ALOHA remains a teaching tool and appears in modern systems like satellite and IoT networks.